L36 SUMMARY OF OUERENT RESEARCHES RELATING TO 



become a dorsal or a ventral according to conditions of pressure. Scales 

 differ according to time of origin, Borne being embryonic and some 

 secondary. They also differ according to function, as is illustrated by 

 the marginals, which hecorae large in exposed situations. The young 

 scale, after the tip has perforated the skin, is very plastic. The exposed 

 supra-orbitals tend to hypertrophy ; the stomodreal scales tend to 

 atrophy. 



Responses of Sessile and Motile Organisms.* — Victor E. Shelford 

 enquires into the different kinds of response in sessile and motile 

 organisms. By responses he means reactions, changes in function and 

 structure induced by external conditions, whether directly or indirectly, 

 quickly or slowly. Thus motile organisms may change their position, 

 colour, etc. ; and sessile organisms may grow in a particular way or 

 adjust their body in relation to a stimulus. Mobile organisms tend 

 largely to behaviour responses, and sessile organisms rather to structural 

 responses. The author emphasizes the need of considering all sorts of 

 responses of both sessile and motile organisms if an adequate theory is 

 to be established. 



Theory of Malignant Tumours. f — Th. Boveri suggested in 1902 

 that malignant tumours might be the result of an abnormal condition 

 of the chromosomes, as, for instance, in pluripolar mitoses. Aichel has 

 sought to combine this suggestion with another, that the beginning of 

 the tumour may be the coalescence of a leucocyte and a tissue cell. 

 But Boveri adheres to his view that the malignant cells result from some 

 nuclear or chromosome defect which they cannot remedy. He passes 

 from cellular to nuclear pathology. 



Effects of Temperature on Tropical Marine Animals.:}: — A. G-. 

 Mayer has experimented on corals and medusa? as to their death- 

 temperatures. Reef corals,- in common with other marine animals, live at 

 temperatures within about 5° of their temperature of maximum activity 

 and within 10° of their death-temperatures. The factor of safety in 

 respect to elevation of temperature is far less in tropical than in temperate 

 marine animals. They are, relatively speaking, poorly adjusted in a 

 physiological sense to their temperature environment. Slight differences 

 produce more serious effects than in the marine animals of the temperate 

 regions. Moreover, tropical marine animals can withstand cooling 

 better than they can survive heating above their normal life-temperature. 

 High temperature appears to cause asphyxiation, the oxygen in the 

 water being insufficient to support the intensified metabolism. 



Feet of Bats.§ — F. De Fenis has made a study of the different 

 types of foot in Chiroptera and the various adaptations exhibited. He 

 recognizes four types : — (a) the adaptation to suspension is at a minimum, 



* Amer. Naturalist, xliii. (1914) pp. 641-74. 



f Zur Frage der Entstehung maligner Tumoren. Jena (1914) 64 pp. See also 

 Anat. Anzeig., xlv. (1914) pp. 477-8. 



X Carnegie Inst. Washington Publications. No. 183 (1914) pp. 1-24 (8 figs.). 

 § Arch. Zool. Exper., liv. (1914) pp. 195-220 (11 figs.). 



