Symposium on J.-L. Dessalles’s Why we Talk (OUP, 2007): Precis by J.-L. Dessalles,commentaries by E. Machery,F. Cowie,and J. Alexander,Replies by J.-L. Dessalles

This symposium discusses J.-L. Dessalles's account of the evolution of language, which was presented in Why we Talk (OUP 2007).     

狭蚤属( Stenoponia J. et R. , 1911)一新种记述(Siphonaptera: Hystrichopsyllidae)

狭蚤属(Stenoponia J.et R.,1911)为大型色深的跳蚤,全身有浓密的鬃,多分布于旧北界,少数在新北界。1959年7月廖灏溶同志从青海Myospalax fontanierii体上采到本属跳蚤,其形态与已知各种均有区别,故订为新种,命名为多棘狭蚤新种S.polyspina sp.nov。     

William J. Bell (1943–1998)

Biography

William J. Bell (1943–1998)     

Oogonial release in Turbinaria conoides (J. Agardh) Kützing (Fucales,Sargassaceae)

The oogonium in Turbinaria conoides (J. Agardh) Kürzing at the time of release is 8-nucleate and consists of 3 wall layers namely exochiton, mesochiton and endochiton. The exochiton contains alginic acid. The mesochiton a mixture of alginic acid and sulphated polysaccharides. The endochiton that is evident in the unreleased 8-nucleate oogonium, stains for sulphated polysaccharides, but is PAS negative. In a released oogonium, the endochiton is Alcian blue and PAS positive and consists of both alginic acid and sulphated polysaccharides.Polysaccharide granules are secreted near the perinuclear region and in thecytoplasmic vacuoles during the initiation of mesochiton. Furthermore, at the distal end the mesochiton froms a pad that fuses with the exochiton. The pad consists of alternate thick and thin bands. The exochiton opens at one side due to the swelling of the oogonium and accumulation of sulphated polysaccharides between exochiton and mesochiton followed by formation and elongation of a mesochiton stalk. The 8-nucleate oogonium is, thus, extruded from the conceptacle, but remains attached to the exochiton by means of a long mesochiton stalk. The secretory paraphyses, at the time of oogonial release, produce copious amounts of polysaccharides. The oogonium is, thus, extruded through the ostiole by the combined efforts of the 3 wall layers that are histochemically and histologically different, in combination with secretion produced by secretory paraphyses.     

Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta,Rhodymeniales) en Méditerranée

Abstract

Presence of Rhodymenia delicatula P.J.L. Dangeard in the Mediterranean. - The presence of Rhodymenia delicatula P.J.L. Dangeard (Rhodophyta, Rhodymeniales) in the southern Thyrrhenian sea is reported. Both cystocarpic and tetrasporic individuals have been collected. Anatomical features of the reproductive structures, as well as the position of these on the thallus allowed the identification of this species formerly known for the Atlantic coasts of Morocco and British Isles.     

Natural wood colouring process in Juglans sp. (J. nigra, J. regia and hybrid J. nigra 23 ×J. regia) depends on native phenolic compounds accumulated in the transition zone between sapwood and heartwood

 Radial distribution of soluble phenolics was investigated at different heights in stems of Juglans nigra, J. regia and hybrids J. nigra 23 × J. regia. Four major phenolic compounds were studied: hydrojuglone glucoside (HJG), quercitrin (QUER) and two unknown compounds characterized as two ellagic acid derivatives E1 and E2. HJG and E1 content increased gradually in the sapwood, peaked in the sapwood-heartwood transition zone, and decreased drastically in the heartwood. QUER was accumulated preferentially around the transition zone, and its content was relatively low in the outer part of the sapwood and in the inner part of the heartwood. E2 content was low in the sapwood and increased in the heartwood. The heartwood formation was marked by the accumulation of new soluble compounds. The relationship between wood extractives and wood colour were evaluated and discussed. HJG was considered to be a major precursor of heartwood colour providing chromophores through hydrolysis (deglucosylation), oxidation and polymerization processes. Received: 2 September 1997 / Accepted: 23 November 1997