ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
295 
The list is not a long one ; it includes Artemia salina ; Daphnia similis , 
otherwise known only from Syria and Palestine ; a large local variety 
of this species ; Alona alluaudi , a large new species ; the remarkable 
Calanid, Diaptomus alluaudi ; Canthocamptus palustris, hitherto found in 
much higher latitudes ; and millions of Pedalion mirum. 
A s the islands are volcanic, the freshwater animals must have been 
borne thither by winds and birds. Most of them are doubtless to be 
found in the adjacent parts of Africa. 
Fauna of Vallombroso.* * * § — Dr. G. Cecconi gives a faunistic list of 
the earthworms, crustaceans, arachnids, and insects of Vallombroso. 
Lacustrine Fauna.j — Dr. O. E. Imhof gives a summary of some 
recent researches. Thus F. Steindachner and J. Richard have co- 
operated in studying the pelagic fauna of Turkish lakes, hitherto un- 
known. The results show agreement with those obtained in Alpine 
lakes, e.g. in the occurrence of Asplanehna helvelica , Daphnella bracli- 
yura, Leptodora hyalina , and Cyclops Leuclcarti. Also of interest is 
the occurrence of Diaptomus Steindachneri, hitherto known only from 
the Jauina lake. Imhof also gives a summary of investigations by 
R. Blanchard and J. Richard on the fauna of high-lying lakes in the 
Alps of Savoy. 
Mollusca. 
Abyssal Molluscs.^ — M. Arnould Locard maintains that the abyssal 
molluscs of the North Atlantic have a wider distribution than is usually 
supposed. On the results of the £ Travailleur ’ and 4 Talisman ’ expeditions 
especially, he bases the conclusion that the fauna in question extends 
over a vast triangle, the apex of which is near Iceland, while the sides 
extend to the European and American continents, and the base line runs 
between Africa and America, about 15° north of the Equator. The apex 
represents a depth of about 50 metres, the African basal angle about 
2000 m., the American angle about 800 m. 
a. Cephalopoda. 
Spindle-Formation in Cephalopod Blastoderm. § — The late Prof. R. 
von Erlanger was led, by his observations on this subject, to the conclu- 
sion that the whole spindle-figure arises in consequence of the influence 
of the central corpuscles on the cytoplasm and karyoplasm. Around 
each central corpuscle the polar radiation arises. Physically or chemi- 
cally the central corpuscle influences the surrounding cytoplasm so that 
the alveoli are arranged in rows converging towards the corpuscle. 
Soon there collects around the central corpuscle a sheath of very finely 
alveolar protoplasm which then attracts fluid out of the nucleus, and 
thus causes all the achromatin substance that is not used in the consti- 
tution of the chromosomes to take the form of the so-called spindle- 
fibres. The centroplasms certainly play an important part in mitosis, 
and even if they are not actually spherical, still deserve their more 
familiar title of attraction spheres. 
* Bull. Soc. Entom. Ital., xxix. (1898) pp. 145-224. 
t Biol. Centralbl., xviii. (1898) pp. 169-73. 
X Comptes Eendus, exxvi. (1898) pp. 441-3. H 
§ Biol. Centralbl., xvii. (1897) pp. 745-52 (4 figs.). 
