Der Phragmoplast der Spermatiden von Spirostreptus spec. (Myriapoda,Diplopoda)

Zusammenfassung Die Spermatiden von Spirostreptus spec. bleiben während der ersten Phasen der Spermiohistogenese durch Zellbrücken miteinander verbunden. Im Bereich der Brücke tritt ein Phragmoplast auf, der zuerst aus Zwischenspindelfasern, einem regelmäßigen Netzwerk endoplasmatischen Retikulums und aus einem kugeligen osmiophilen Körper besteht. Die osmiophile Substanz wird stark vermehrt und erstreckt sich in die Zellbrücke, während das endoplasmatische Retikulum dort verschwindet. Vor der Durchtrennung der Zellbrücke ziehen sich das granulierte Material und die Spindelfasern aus der Zone der trennenden Zellmembran zurück. Dort erscheinen dann Bläschen und konfluieren zu den Zellmembranen.

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The phragmoplast in the spermatides of Spirostreptus spec. (Myriapoda, Diplopoda)

Summary During the early phases of the spermiohistogenesis the spermatides of Spirostreptus spec. are connected by cell bridges. In the region of the bridge a phragmoplast appears which at first consists of continuous spindle fibres, a regular network of endoplasmatic reticulum and a spheric osmiophilic body. The osmiophilic substance increases and extends into the cell bridge while the endoplasmatic reticulum is disappearing there. Before the cell bridge is divided the granulated material and the spindle fibres retract from the zone of the separating cell membrane. Then there are appearing vesicles which fuse to the cell membrane.

     

Der Haustorienkomplex von Erysiphe betae (Vanha) Weltzien

The haustorial complex of Erysiphe betae (Vanha) Weltzien The haustorial complex of Erysiphe betae resembles the type of haustorium of other powdery mildew species on dicotyledonous plants. A collar of polysaccharide material with an invaginated electrondense channel surrounds the septed infection peg. The nearly elliptic haustorial body with appendices at both poles is surrounded by the plasmalemma, which had been transferred to the extrahaustorial membrane. Dictyosomes and endoplasmatic reticulum are presumably be involved in this process. Haustorial body and appendices contain many mitochondria, and with progressing senescence, the number of vacuoles with partly membrane-like inclusions increases.     

Der Kernphasenwechsel von Valonia utricularis (roth) ag

Ohne ZusammenfassungMit 3 Textabbildungen (43 Einzelbildern).     

Der Chromosomencyclus von Macrosiphum pisi Kalt (Aphididae)

Ohne Zusammenfassung     

Der Feinbau des Spermatozoids von Sphaeroc arpos donnellii Aust. (Hepaticae)

Zusammenfassung Das reife, aus dem Antheridium entlassene Spermatozoid setzt sich aus den drei Abschnitten: Kopfteil, Kernabschnitt und dem daran anschließenden Plasmastück zusammen. Im Kopfabschnitt entspringen die beiden Geißeln. Jede Geißel zeigt den typischen Aufbau von neun randlichen Doppelfibrillen um zwei zentral gelegene Fibrillen. Zwischen den peripher und zentral liegenden Fibrillen, deren Durchmesser etwa 200 Å beträgt, bestehen Verbindungen, die zum Teil als etwa 70 Å breite, hohl erscheinende Fibrillen ausgebildet sind. Die Geißel wird von einer etwa 100 Å dicken Doppelmembran umgrenzt. Im Kopfabschnitt befindet sich ein membranhaltiger Körper, der als stark umgewandeltes Mitochondrium oder als Plastide anzusehen ist.Der Kernteil wird fast ganz von dem höchstens 0,4 breiten und etwa 13 langen Kern eingenommen. In der dichten Kernsubstanz sind etwa 25–40 Å breite Fibrillen erkennbar, die gelegentlich eng zu dickeren Bündeln zusammengepackt sein können. Eine typisch ausgebildete doppelte Kernmembran fehlt. Selten läßt sich eine nur 40–60 Å breite, stark kontrastierbare Linie feststellen, die möglicherweise als extrem reduzierte Abgrenzungsmembran des Kerns gedeutet werden kann. Zwischen dem Kern und der das ganze Spermatozoid umschlie\enden, doppelten, etwa 80–100 Å dicken Membran, die als etwas verbreitertes Plasmalemma anzusehen ist, kann sich ein schmaler Cytoplasmastreifen einschieben.Das Plasmastück umfaßt den großen Leukoplasten, Mitochondrien, Membranen des endoplasmatischen Reticulums, multivesikuläre Körper, kleinere Vesikel und gelegentlich Vacuolen. Im Innern des Leukoplasten befinden sich zahlreiche, bis zu 0,2 große Stärkekörner und nur selten einige Reste des Membransystems. Die Mitochondrien besitzen im Vergleich zu den entsprechenden Zellorganen der Spermatiden eine oft stark veränderte Struktur. Ferner treten im Plasmastück Körper auf, die von einer Doppelmembran umgeben sind und in ihrem Innern Doppelmembranen aufweisen. Sie gleichen in ihrem Bau völlig dem membranhaltigen Körper im Kopfabschnitt und dürften stark umgeformte Mitochondrien oder Plastiden darstellen.Unmittelbar unter der Spermatozoidmembran befindet sich eine für Pflanzenzellen ungewöhnliche Struktur, die als Fibrillenscheide bezeichnet wird, und die sich meistens vom Kernabschnitt bis in das Plasmastück der Zelle ausdehnt. Die 400–800 Å dicke Fibrillenscheide besteht aus bis zu 30 nebeneinander liegenden, hohl erscheinenden Fibrillen mit einem Durchmesser von etwa 180–220 Å. Die beiden endständigen Fibrillen jeder Scheide besitzen einen größeren Durchmesser von etwa 300 Å. Die Fibrillen werden von einer Doppelmembran gegen die Spermatozoidmembran und andere Teile der Zelle abgegrenzt.Spätestens beim Eindringen des Spermatozoids in den geöffneten Archegonhals wird das Plasmastück abgestreift. Das bis zur Eizelle vorgedrungene Spermatozoid besteht nur noch aus dem Kopfabschnitt und dem anschließenden Kernteil.

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The fine structure of the spermatozoid of Sphaeroc arpos donnellii Aust. (Hepaticae)

Summary The structure of the spermatozoid of the liverwort, Sphaerocarpos donnellii, was investigated under the electron microscope after fixation in potassium permanganate, osmium tetroxide or glutaraldehyde with postfixation in osmium tetroxide. Mature, newly emerged spermatozoids consist of three parts: Head end, nuclear piece and the attached cytoplasmic part. The two flagella originate in the head end. They show the typical structure of nine outer double fibers around two fibers in the middle. Connections exist between the central and the outer fibers. At least to some extent they are composed of thin, tubular fibers, about 70 Å in diameter. The head end contains a body which may be regarded as a modified mitochondrion or a plastid.Nearly the whole space of the nuclear piece is occupied by the nucleus, with a length of a about 13 and a thickness up to 0,4 . The dense nuclear content shows above all, approximately 25–40 Å thick fibers, which are often packed closely together. A typical double membrane as nuclear envelope is not recognizable. Rarely one observes a dark line, not thicker than 40–60 Å which may be interpreted as limiting membrane of the nucleus. A thin band of cytoplasmic material may be interposed between the nucleus and the double membrane, which has a thickness of about 80–100 Å and surrounds the whole spermatozoid.The cytoplasmic piece includes the big leucoplast, mitochondria, membranes of the endoplasmic reticulum, multivesicular bodies, small vesicles and occasionally vacuoles. The interior of the leucoplast is filled with numerous starch granules, up to 0,2 in diameter. Only rarely some remains of the thylacoid system appear. The mitochondria show a modified fine structure compared with the corresponding organelles in the spermatids. The cytoplasmic end comprises bodies which are limited by a double membrane and which contain double membranes. They are absolutely alike the membraneous body in the head piece and have to be regarded as modified mitochondria or plastids.Immediately below the membrane of the spermatozoid one recognizes a structure, named Fibrillenscheide=fibrous sheath, which in most cases expands from the nuclear piece into the cytoplasmic part. The 400–800 Å thick fibrous sheath consists of up to 30 fibers lying side by side, each with a diameter of about 180–220 Å. The fibers at both ends of the fibrous sheath possess a diameter of about 300 Å. A double membrane encloses all the fibers together and separates them from the limiting membrane and other components of the spermatozoid.The cytoplasmic end is lost, at the latest when the spermatozoid enters the open neck canal of the archegonium. The spermatozoid which has reached the egg cell is composed only of the head end and the nuclear piece.

     

Der frühlarvale Köcherbau von Micrasema longulum McL. (Trichoptera,Brachycentridae)

Case Construction of Young Larvae of Micrasema longulum McL. (Trichoptera, Brachycentridae) The method of case building used by the first three larval instars of Micrasema longulum is described. The initial case is constructed above the hatching aperture in the jelly of the egg mass, in the same way as it is done by other species of Brachycentridae. The material of the initial case is caught from drifting particles in running water. From the end of the first larval instar only silk is used for the extension of the case. Two silken layers of a very regular pattern are to be distinguished. The construction of the cloverleaf-shaped posterior aperture is described. Some of the methods used for the case building show a maturing process during ontogenesis.     

Functional organization of the arctiid moth tymbal (insecta,lepidoptera)

The exoskeletal morphology, muscular organization, and innervation patterns of the tymbals of seven sound-producing species of tiger moths (Arctiidae) were compared with the undifferentiated episterna of two silent species. At least three muscles are involved in sound production: the tymbal muscle, pv2, and the accessory muscles, pvl and/or pv6. All of the tymbal muscles are innervated by the IIIN2a branch of the metathoracic leg nerve, which contains two axons larger than the others. Backfills of the tymbal branch of the IIIN2a reveal a medial sensory neuropil and a population of five ipsilateral motor neurons whose somata are clustered into three groups along the anterior edge of the metathoracic ganglion. The dendritic arborizations of the motor neurons extend to the ganglionic midline but are separate from one part of the auditory neuropil observed in other noctuoids. The study concludes that the arctiid tymbal reveals only minor modifications (e.g., cuticle thinning) of the episterna of silent moths and represents a primitive form of the tymbal compared to those of the Cicadidae.     

Iridoid glycosides in the butterfly Euphydryas cynthia (lepidoptera,nymphalidae)

Larvae and pupae of the alpine butterfly Euphydryas cynthia contain three iridoid glucosides: two of them, aucubin and catalpol, are very common in the Plantaginaceae, but the third, 6-O-glucopyranosylaucubin, has hitherto only been isolated from Odontites verna and Verbascum sinuatum (Scrophulariaceae). The amounts of the three iridoids found in the insects were 0.53, 0.31 and 1.48 % dry wt, respectively. Preliminary feeding experiments with an insectivorous bird indicated some unpalatability in the insect, which probably stems from the iridoid content.     

Der Generationswechsel von Rotalia beccarii var. flevensis,nov. var

Zusammenfassung Rotalia beccarii var. flevensis nov. var. zeigt eine typische Trimorphie (Formen a₁, A₂ und B). Diese Trimorphie ist der Ausdruck eines Generationswechsels, der mit den Jahreszeiten gleichen Tritt hält. Die B-Form ist die Dauerform im Winter und bildet im Frühjahr durch asexuelle Vermehrung Plasmodiosporen, welche zur A₁-Form heranwachsen. Die A₁-Form bildet ihrerseits im Sommer die A₂-Form, welche gekennzeichnet ist durch den Besitz eines Chromidiums. In dieser Form entwickeln sich die Mikrosporen durch mitotische Teilungen der aus dem Chromidium entstandenen kleinen Kerne, nachdem die Individuen sich enzystiert haben. Die Kopulation der Mikrosporen liefert im Herbst wieder die mikrosphärische B-Form.Ich habe eine ausführliche Studie publiziert über die Fortpflanzung der Foraminiferen in: Siboga-Reports 4, Part II, S. 79–104. Daselbst ist diese Rotalia noch als Pulvinulina repanda angeführt. Für Figuren verweise ich auf diese Arbeit.Mitteilung der Kommission zur biologischen Untersuchung der Zuidersee während der Trockenlegung.     

Der Farbstoff von Cordyceps militaris L.

Zusammenfassung Der orange-rote Farbstoff von Cordyceps militaris L. stellt ein in Wasser leicht lösliches Carotinoid dar, das dem Crocin nahe zu stehen scheint.Herrn Prof. Dr. Walter Mevius zum 65. Geburtstag gewidmet.     

On the phylogenetic significance of two miocene zygaenid moths (insecta,lepidoptera)

Two Miocene zygaenid moths (Insecta, Lepidoptera), »Zygaena« miocaenica Reiss andZygaenites controversus BuRGEFF, both from the Schwäbiscne Alb in south-western Germany, are redescribed and illustrated in detail. Comparison with a cladogram of the Zygaeninae illustrates that they belong to two different genera, i. e. to two different evolutionary lines of the subfamily. Characters in the venation ofZygaenites controversus demonstrate its close relationship to the extant genusEpizygaenella. However, there are no specific characters in »Zygaena« miocaenica which would allow a precise assignment of that species, altough it clearly shows derived characters of the (Praezygaena + Reissita + Epizygaenella + Zygaena) group. This ist the most advanced subdivision of the Zygaeninae, which orginated in the Afrotropics, although the main radiation occurred in Eurasia.     

Der Einfluss von Lithium-Ionen auf die Embryonalentwicklung meroblastischer Wirbeltierkeime (Salmo irideus)

Ohne Zusammenfassung     

Der Einfluss einiger Schwermetallsalze (Zn,Cd, Mn,Fe) auf die chemische Zusammensetzung von Aspergillus niger

Ohne ZusammenfassungMit 4 Textabbildungen.Dissertation der Mathematisch-Naturwissenschaftlichen Fakultät der Friedrich-Wilhelms-Universität zu Berlin.     

Amplification dynamics of human-specific (HS) Alu family members.

We have investigated the distribution of several recently inserted Alu family members within representatives of diverse human groups. Human population studies using 65 unrelated human DNA samples, as well as a familial study to test inheritance, showed that individual Alu family members could be divided into three groups. The first group consisted of relatively older Alu family members which were monomorphic (homozygous) throughout the population tested (HS C3N1 and C4N6). The second group (HS C4N2, C4N5 and C4N8), apparently inserted into other repetitive regions of the genome, resulting in inconclusive results in the PCR test used. However, it is clear that these particular Alu insertions were present in a majority if not all of the loci tested. The third group was comprised of three dimorphic Alu family members (HS C2N4, C4N4 and TPA 25). Only a single Alu family member (TPA 25) displayed a high degree of dimorphism within the human population. This latter example also showed different allele frequencies in different human groups. The isolation and characterization of additional highly dimorphic Alu family members should provide a useful tool for human population genetics.     

On interference among larvae of the greasy cutworm,Agrotis ypsilon rott. (lepidoptera: Noctuidae)

Summary The greasy cut worm,Agrotis ypsilon Rott., has a characteristic habit; the larva feeds on the small seedling of the host plant. Studies in a population in outbreak area suggested that the food shortage temporally took place, causing the reduction of weights of pupae and adults. The fact that this species depends on the small seedling as the host seemed to be responsible for this food shortage. However, it was found that the larval crowding also affected the body weight, even if the food was supplied in excess. It was further suggested that the weight reduction is due to the injury caused by the encounter of larvae. The oviposition habit to lay small egg masses and the aggressive behaviour of the larva was considered to be responsible for the uniform distribution at the later larval stage. Probably, the larval dispersion enabled the larva to forage in the most effective way as well as it protected the larva from the attack of another ones. As a result, this would enable the maximum number of individuals to survive. It seemed that the functions noted above did not work in the population being under outbreak condition, because the larval density was unusually high due to mass-invasion of moths.