724 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



sentatives of the general circumpolar fauna, and are found also on the 

 northern coast of Europe and Asia. The Amphipod fauna of Labrador 

 is very similar to that of Norway, the differences naturally becoming 

 greater as we pass southward along the shores of the two continents. 

 Nevertheless there are not a few species common to the Mediterranean 

 and the southern coast of New England. The tendency of some investi- 

 gators to describe a species as new when met with for the first time in 

 North America, has, therefore, resulted in the production of many 

 synonyms. Like others of the series, the diagnostic key submitted is 



of great value 



Annulata. 



Sperm Centrosome and Aster of Allolobophora foetida.*— Katharine 

 Foot and E. C. Strobell point out that during the past few years evidence 

 has accumulated which assigns to the egg attraction-sphere a position 

 where it threatens to usurp all the functions hitherto claimed for the 

 male attraction-sphere. This promotion of the egg-centrosome and 

 aster, with its satellites the cytasters, seems to have been at the expense 

 of the male centrosome, until even Boveri suggests the hypothesis that 

 instead of the spermatozoon bringing a centrosome into the ovum, it 

 may be that it simply induces the formation of a centrosome, from 

 whose division all that follow are derived. 



The egg of Allolopliora furnishes evidence that the centrosome of its 

 male attraction-sphere is part of the spermatozoon itself, but Allolobophora 

 fails to offer any evidence that this centrosome gives rise to one or both 

 of the cleavage centrosomes. On the contrary, the evidence points to the 

 de novo origin of the cleavage centrosomes. 



Role of Amoebocytes in Polymnia nebulosa.f — M. Siedlecki has 

 an interesting study of the varied role of the ccelomic amoebocytes in 

 this Annelid. He describes their phases, e.g. the tendency to agglutinate 

 in plasmodia — a tendency which he attributes largely to the viscosity of 

 the surfaces of the amoebocytes. The engulfing of foreign bodies was 

 watched, and is described. Reasons are given for believing that they are 

 important in dealing with the sporozoon parasites, such as the free cysts 

 of CaryotropM. Of particular interest is the description of the way in 

 which the amoebocytes utilise the cytophores formed in the spermato- 

 genesis. The expense of reproduction is thus lessened. 



Observations on the Japanese Palolo (Ceratocephale osawai sp. n.)4 

 Akira Izuka gives the characters of this new species, and discusses at 

 some length its swarming habits, which he studied on the Sumida river, 

 Tokyo. The sexually mature worms swim out four times a year in the 

 months of October and November. The swarming period extends from 

 one to four consecutive days, immediately following the days of the new 

 and the full moon. There is a parallelism between the occurrence of 

 the densest swarm and the highest spring tide during the months con- 

 cerned. The genital products are discharged while the worms are 

 actively swimming. 



* Amer. Journ. Anat, ii. (1903) pp. 365-9 (1 pi.). 



t Ann. Inst. Pasteur, xvii. (1903) pp. 449-62 (2 pis.). 



X Jour. Coll. of Science, Imp. Univ. of Tokyo, xvii. art. 11, pp. 1-37 (2 pi.). 



