ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 437 



The probable systematic position of the genus is interesting ; it 

 represents in certain respects a transition from the Dendrochirota to the 

 Molpadiidae. 



Maturation in Asterias glacialis.* — M. Hartmann finds that in 

 the growing period of the ovarian egg, there are " vegetative nuclear 

 changes," consisting in the distribution of the chromatin in the nucleus 

 and its accumulation in the nucleolus. ♦*>«( 



At the end of this period all the chromatin and plastin is united in 

 the nucleolus, from which after liberation into the water and after the 

 radiation and dissolution of the germinal vesicle there arise the chromo- 

 somes of the first directive-division. 



This is confirmatory of the work of 0. Hertwig (1878) and of what 

 Carnoy and Lebrun observed in Urodela. It cannot be readily har- 

 monised with the assumption of the individuality and qualitative 

 diversity of the chromosomes. 



Echinoderms from Puget Sound. j — H. L. Clark reports on collec- 

 tions which include some interesting new species : — Pteraster multi- 

 soinosus, Cribrella spiculifera, Psolus chitonoides, and Cucumaria lubrica. 



Function of Sphaeridia in Sea-Urchins.J — Yves Delage has made 

 a number of experiments to test the theory that the sphaeridia are equili- 

 brating organs. He experimented with Strongylocentrotus lividus and 

 Echinus esculentus, watching the behaviour of the animals after the re- 

 moval of the sphaeridia. His results were negative, for the urchins 

 operated on moved and turned themselves and climbed up vertical sur- 

 faces almost as effectively as uninjured specimens. They were slow 

 and hesitating in righting themselves when inverted, but they did it. 

 Delage concludes cautiously that the sphaeridia are not the exclusive 

 organs of orientation. 



Genital Pores of Male Antedon rosacea.§ — W. S. Marshall de- 

 scribes pores penetrating nearly through the wall of the pinnules. As 

 many as four pores were found on a single pinnule, with no very definite 

 position other than being in the neighbourhood of the sacculi. Many 

 were full of spermatozoa and in one specimen the pore was ruptured. 



New Crinoid.|| — 0. Follmann describes a new form Hystricrinus 

 schwerdii from lower Devonian strata near Coblenz. It is related to 

 those Hexacrinids which have a tripartite basis (Hexacrinus Aust. and 

 Arthracantha Williams = Hystricrinus Hinde), but is distinguished by 

 the cirri on the stalk, the three different kinds of joints occurring in 

 the stalk, the numerous small polygonal plates composing the calyx lip, 

 and so on. 



Ccelentera. 



Relationships of the Rugosa to Living Zoantheae.l — J. E. Duerden 

 finds from a study of sections of Lophophyllum proliferum that the tip 



* Zool. Jakrb., xv. (1902) pp. 792-812 (2 pis.). 

 t Proc. Boston Soc. Nat. Hist., xxix. (1901) pp. 323-37 (4 pis.). 

 X Comptes Rendus, cxxxiv. (1902) pp. 1030-3. 

 § Zool. Anzeig., xxv. (1902) pp. 209-11 (2 figs.). 

 || Verh. Nat. Ver. Preuss. Kheinl., lviii. (1901) pp. 66-76 (1 pi.), 

 t Johns Hopkins Univ. Ciro., xxi. (1902) pp. 19-25 (12 figs.); Ann. Nat. Hist., 

 x. (1902) pp. 381-98 (12 figs.). 



