1308 Journal of Applied Microscopy 



is the next topic discussed. It is believed that the cytoplasm has to do prima- 

 rily with the relation of the organism to the external environment, i. e., with the 

 reactions to stimuli ; while, on the other hand, the nucleus, as a result of its as- 

 similatory activity which conditions growth and reparation, enables the organism 

 to continue living. In this section the author offers some very interesting and 

 suggestive theories as to the physiological significance of the division of organ- 

 ism into cells, and the phylogenetic origin of the nucleus. In a short section on 

 cell and nuclear division it is maintained that the centrosome is the part of the 

 cell essentially concerned with these processes. 



In concluding, Schenck condemns the view that " cell physiology " is synony- 

 mous with " general physiology," and even considers that the attention which 

 has been paid to the former has tended to hinder the progress of the latter. The 

 work is throughout one of interest, and in many respects, of value. The style is 

 uncommonly clear and straightforward. The thing which most mars the work 

 is the polemic character which pervades the whole and at times descends to ab- 

 surd personalities. r. p. 



Cole, L. J. Notes on the Habits of Pycnogo- This paper, although brief, furnishes 

 nids. Biol. Bull. 2: iqi;-207. iqoi. . •, ,• 



an important contribution to our 



knowledge of the general physiology of the somewhat neglected group, the 

 Pycnogonida. The principal points treated are the movements and the reactions 

 to light, both of which are described in detail. Two curious facts brought to 

 light in connection with the movements are : (a) the action of the legs is pre- 

 cisely the same in both the swimming and crawling movements ; and (b) the 

 stroke of the anterior legs is found to be stronger than that of the posterior, and, 

 since the action of both is qualitatively the same, it results from the structural 

 relations of the body that the posterior legs act as hindrance to forward move- 

 ment when the animal is crawling. The pycnogonids studied are shown to be 

 positively phototactic, but the precise form of the orientation differs according 

 as the animal swims or crawls. When crawling towards the light the anterior 

 end of the body precedes, while when sivimming towards the light the posterior 

 end is in advance. The reaction is the same in the two cases, but the result is 

 conditioned by the mechanical relations of the animal to a solid object, i. e., the 

 bottom. This point is of considerable theoretical interest as indicating that the 

 essential thing in an orientation is not the getting of one end of the organism to- 

 wards or away from the source of the stimulus, but is. on the contrary, the 

 placing of the axes of the body in definite relations to the lines of action of the 

 directive stimulus. The transfer of the eggs from the female to the male was ob- 

 served and found to be a comparatively simple process, apparently involving no 

 psychic activity on the part of the animals. R. p. 



Ritter, W. E., and Congdon, Edna M, On the In- The question as to the effect of an arti- 

 hibition by Artificial Section of the Normal r • \ ^- c -i-^l^^ 



Fission Plane in Stenostoma. Proc. California ^Cial section of an animal JUSt about tO 

 Acad. Sci. (Third Series). Zoo). 2 : divide by fission was suggested to the 

 3 5-37 ' P • xv"> 9 • senior author of this paper, in the 



course of his work on monogenesis in ascidians. A partial answer is gained from this 

 study of the common rhabdocoele turbellarian Stenostoma leucops O. Schm. The 



