SOME ASPECTS OF THE BIOLOGY OF THE MARINE LEECH HEMIBDELLA SOLEAE

The biology of the marine leech Hemibdella soleae was studied. It was found that multiple infections were common, the leeches being attached by the posterior sucker to spines on the ctenoid scales of the upper surface of the sole. It was observed that in aqqaria they change position every few days, tending to migrate antoriorly and this orientation may perhaps be directed by the arrangement of the scales.
Cocoons, which are not deposited at 8 C or below, are attached to the shell fragments with which the soles camouflage themselves and the young leeches hatch after about forty-one days at 17 C. Leeches reach maturity about twenty-three days after finding a host and are fully grown after a further fortnight.
British Hemibdella seem to be confuned to Soleu solea although several other hosts (All Soleidae) have been recorded for this leech in the Mediterranean.     

ASPECTS OF THE PHYSIOLOGY OF THE SHEEP TICK

Recent work on the ecology of the sheep tick has posed many problems of a physiological nature that could best be investigated by laboratory or by combined laboratory and field studies. Three subjects of relevance to sheep tick ecology are briefly considered in the following paragraphs.     

A COMPARISON OF SOME ASPECTS OF THE PHYSIOLOGY AND METABOLISM OF THE NERVOUS SYSTEM OF THE LOCUST SCHISTOCERCA GREGARIA IN VITRO WITH THOSE IN VIVO

Abstract— Studies were made on isolated ganglia of the locust in a modified O₂ electrode. The basic requirements of a suitable incubation medium were determined and found to include saturation of the medium with 100% O₂, and 10m m -glucose as energy source. The effects of incubation in vitro were determined for a number of biochemical characteristics including O₂ uptake and the concentrations of Arg P, ATP, ADP, glycogen, glucose, lactate and pyruvate. Action potentials were recorded from a major nerve both in vivo and in vitro. On the basis of these biochemical and physiological studies, it was concluded that the tissue functions well in vitro. Some comparisons were made between the metabolic characteristics found in the locust nervous system, and those of mammalian tissue. The locust ganglia were found to have a rate of O₂ uptake much higher than comparable mammalian tissue, and to contain a considerable reserve of glycogen. The low ratio of lactate/pyruvate suggests a more aerobic metabolism than is the case in mammalian brain.     

磁场处理番茄种子对其生理生化影响的研究

磁场处理番茄种子观察种子的发芽率,幼苗的过氧化氢酶（ＣＡＴ）和过氧化物酶（ＰＯＤ）活性的变化,以及对过氧化物酶同工酶的影响。实验结果表明,磁场强度在１０００￣２０００ＧＳ范围内,种子发芽率最高,过氧化氢酶和过氧化物酶活性最高,过氧化物酶同工酶活性亦最高,磁场强度高于３０００ＧＳ时,种子发芽率及其酶活性随之降低。