212 SUMMARY OF CURRENT RESEARCHES RELATING TO 



i] umber and size of their annuli. The type of differentiation represents 

 essentially a type of colonial senescence. 



In aquaria in which intact colonies of Clytia baJceri developed as in 

 nature, it was found that stems cut at given levels regenerated in 

 certain respects not according to the original type for that level, but 

 according to the type characteristic of the distal or youngest member of 

 the stem. This result indicated a general physiological change through- 

 out the stem correlated with advancing age. 



Effect of Light on Obelia.*— H. B. Torrey and A. L.Martin 

 find that a given stem of Obelia regenerates from a distal cut two 

 or three hydranths in the time required for the production of one 

 hydranth by a similar stem under similar conditions, except that it 

 develops in daylight. The annuli on the pedicels supporting the 

 hydrothecte are more numerous in the darkness specimen. The effect 

 of light on Obelia is to retard growth and differentiation — the opposite 

 to what Loeb found in Eudendrium. 



Porifera. 



Hexactinellid Spicules.! — R. Kirkpatrick, in a continuation of his 

 classification of these spicules, points out that clavulae and scopula? are 

 holactine micromonactins, and suggests that their spines and disks 

 should be termed centrospines and centrodisks, to distinguish them from 

 the true end-spines and end-disks at the distal end of the actines of 

 astral spicules. He also notes that microhexactins, which he spoke of as 

 absent in Hexasterophora, occur in certain dictyonine species, but appear 

 to be entirely absent from most of the Hexasterophora. 



Protozoa. 



New Species of Cassidulina.J — Henry Sidebottom describes and 

 figures Cassidulina eJegans sp. n., and C. decorata sp. n., both from the 

 S.W. Pacific. 



Fat in Ciliated Infusorians.§ — Witold Staniewicz has made experi- 

 ments on Paramecium, Stentor, and other Infusorians in regard to the 

 use they make of fat. He shows that the Infusorians are able to ingest 

 fat, but they do not break it up or emulsify it. The fat found in the 

 cells of Infusorians is due to substances which they can digest, especially 

 proteids and carbohydrates. It seems that no Protozoa can digest fat, 

 whereas all Metazoa can. 



New Flagellate in Pelagic Copepod.|| — E. Chatton describes 

 Paradinium poucheti g. et sp. n., found in the general cavity of Acartia 

 rlausi Giesbrecht. There is a massive plasmodium, fragments of which 

 pass out by the gut of the host, forming cysts which sporulate. Before 

 the spores acquire their flagellate form they are amoeboid, and these 



* Advance print, Proc. 7th Internat. Zool. Congress, Boston 1907, published 

 (1910) 1 p. f Ann. Nat. Hist., v. (1910) pp. 347-50 (5 figs.). 



J Journ. Quekett Micr. Club, 1910, pp. 103-8 (1 pi.). 

 § Bull. Acad. Sci. Cracovie, 1910, pp. 199-214 (1 pi.). 

 || C.R. Soc. Biol. Paris, lxix. (1910) pp. 341-3.| 



