326 SUMMARY OF CURRENT RESEARCHES RELATING TO 



chlorophyll, some parts are digested and retained in the form of baso- 

 phil globules and fat, while others are excreted from the cells into the 

 gut in the form of strongly acidophile grains. 



Echinoderma. 



Regeneration of Spines and Pedicellarise in Sea-urchins.* — 0. Poso 

 has experimented with Sphatrechinus granulans, Echinus microtuber- 

 culatus, and Strongylocmtrotus lividus, and finds that there is regeneration 

 of spines and pedicellariae. He was led to this research by the state of 

 some of the sea-urchins collected at Naples some time after the eruption 

 of Vesuvius in 1906, which showed delicate spines, disproportionately 

 young looking. On a sudden change from a large reservoir to a small 

 glass vessel a specimen of Sphavrechinus shed most of its spines and 

 seemed about to die. It recovered, however, and began to regenerate 

 what it had lost. 



Luminosity of Ophiuroids. — Reichensperger f has studied Ophiop- 

 sila annulosa (Sars), 0. aranea Forbes, Amphiura flliformis Midler, and 

 A. squamata Sars. In the first there are peculiar glandular structures 

 in the lateral spines ; in A. flliformis there are similar structures in all 

 the spines. In A . chiqjei, which is not luminous, there are no glandular 

 structures of this sort, but they occur again in A. squamata. In 

 0. aranea, however, they are not to be found. Reichensperger thinks 

 that in the three species above noted the glandular structures associated 

 with the spines are the luminous organs. He does not agree with 

 Irene Sterzinger's conclusion that in A. squamata the tube-feet produce 

 luminous mucus. 



Ernst Mangold % has studied the same four species, and he also has 

 concluded that the luminosity is associated with skeletal plates and spines, 

 not with tube-feet. He criticises Irene Sterzinger's argument. He also 

 discusses the climbing powers of Ophiuroids, and concludes that the 

 attachment of the tube-feet is not mainly due to a secreted glutinous 

 substance. The theory that the fixation is due to glutinous secretion 

 is not convincing. There is more to be said for the theory that the 

 tube-feet may act as muscular suckers. 



Development of Ophiothrix fragilis.§ — E. W. MacBride communi- 

 cates the results of his investigation of this subject. The early develop- 

 ment varies with the condition of the egg at the moment of fertilisation, 

 and the development of the unripe egg resembles in certain features that 

 of Ophiura brevis. The ccelome originates as a single vesicle from the 

 apex of the archenteron, and this appears to be true for all classes of 

 Echinoderms. This segments into three somites on each side. The 

 middle somite on the right occasionally assumes a five-lobed form, 

 proving beyond doubt that it is a right antimere of the water-vascular 

 system. Metamorphosis is initiated by a preponderant growth of the 

 organs of the left side, which affects the larval arms and the sides of 

 the oesophagus, and which not only carries the hydroccele round the 



* Anat. Anzeig., xxxii. (1907) pp. 14-16. 



t Biol. Centralbl. xxviii. (1908) pp. 166-8. J Tom. cit., pp. 169-76. 



§ Quart. Journ. Micr. Sci., li. (1907) pp. 557-606 (6 pis, 4 figs.). 



