618 SUiMMARY OF CURRENT RKSEARCMES RELATING TO 



tonus function, such as is seen in sea-anemones and ascidians and other 

 types poor in reflexes. The marginal nervous system has a regulatory 

 function in relation to the umbrellar musculature, reducing the reflex 

 excitability. 



Stromatoporoids and Eozoon.*— R. Kirkpatrick recently announced 

 his view that Stromatoporoids are Sponges. He was led to this con- 

 clusion by the presence of siliceous spicules, similar to those formed in 

 Merlia and MonticuJipora. He now states that he was misled, for it has 

 become evident to him that the supposed spicules are the calcified 

 chitinous rings and half-rings belonging to the canals and chambers of 

 Foraminifera. It is now clearly obvious also that the calcareous 

 skeleton of Stromatoporoids has a structure similar to that of the higher 

 forms of Perforate Foraminifera. Kirpatrick also maintains that Eozoon 

 canademe is a Foraminiferan. Its calcareous skeleton shows clearly the 

 Foraminiferal structure of pores and tubuli, and, further, chitinous 

 rings and coils are present. It is nearly related to Labechia and 

 Beatricea. Many of the Caunopora tubes so frequently found in 

 Stromatoporoids are not corals, but Chstopod worms, apparently be- 

 longing to the Spioniformia. Kirkpatrick has found what appears to be 

 a similar kind of worm in the living MonticuUpora {Merlia) normani at 

 Porto Santo. 



Stromatoporoids and Eozoon.f— R. Kirkpatrick gives the following 

 interpretation of Stromatoporoids. They are adherent colony-forming 

 Perforate Foraminifera, each unit in one group of Stromatoporoids 

 consisting of a central and circumambient chamber followed by spiral 

 series of simple rather thick-walled chambers, with the walls perforated 

 by pores and tubuli. The growth is like that of the Imperforate genus 

 Orhitoides, which has only vertical radial partitions, and not horizontal 

 ones in addition, as in Orhitoides. " In another group— Labechiidte — 

 the central chamber and immediately succeeding growth somewhat 

 remind one of the Globigerina type." 



Similarly, Eozoon is a colonial Perforate Foraminiferan, each unit 

 being a coiled shell of the Nummulitid type, but without alar pro 

 longations as in Nummulites. It is suggested that Eozoon was the 

 ancestor of the Nummulitid^, and tliat the Stromatoporoids were the 

 predecessors of some of the spirilline, rotalian, and acervuline Rotaliidse. 



Germinal Localization in Berbe.|— Naohide Yatsu has experi- 

 mented with the egg of Bero'e ovata, and corroborates on the whole the 

 work of Fischel. Germinal localization becomes more definite after the 

 formation of the polocytes. Before this there does not seem to be much 

 definite localization of the germinal material for the future comb-plates 

 and endodermal pockets. Each of the twin embryos produced from an 

 Qgg by an equatorial section before the first cleavage may possess the 

 apical sense-organ. Since some of the l)lastomeres of the eight-cell 



* Ann. Nat. Hist., x. (1912) pp. 341-7 (2 pis.), 

 t Ann. Nat. Hist., x. (1912) i^p. 446-60 (2 pis.). 

 X Ann. Zool. Japon, viii. (1912) pp. 5-13 (25 figs.). 



