ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 385 



medulla participate in the enlargement, but the hypertrophy of the 

 cortex is somewhat gi'eater than that of the medulla. The adrenalin 

 content increases. The rats not infrequently die suddenly while 

 apparently thriving. This is due to rapid cardiac hypertrophy. 



Variation of Common Lizard.* — G. A. Boulenger gives an account 

 of the great variability in the scales (lepidosis) and coloration of Lacerta 

 vivipara ; and notes that it is highly remarkable that a species which has 

 such a wide distribution, and lives under such varied conditions of 

 climate and soil, should show no definable geographical races. The 

 variations recorded are purely individual. The species is the most 

 widely-distributed member of the genus, and probably one of the most 

 ancient. Boulenger regards it as derived from L. agilk, and as leading 

 to the Oriental genus Tacliydromus. So far as is known at present it is 

 the only species of Lacertida3 which can be called viviparous. 



INVERTEBRATA. 

 Mollusca. 



°-- Cephalopoda. 



Sensory Reactions of Cuttlefish. f — Marie Goldsmith has made 

 a number of interesting experiments on cuttlefishes. She proves their 

 capacity for distinguishing colours. Red is no exception and can be 

 distinguished from black. Associations can be established between the 

 colour of an object and its edibility, even when neither the colour nor 

 the object is part of the animal's normal environment. These associa- 

 tions permit of the establishment of memory, which is, however, of 

 short range. The power of remembering is facilitated by repetition, 

 and it disappears gradually. Recollection of tactile impressions seems 

 to last longer (eight hours) than that of visual impressions (three hours). 



Arthropoda. 



a. Insecta. 



Stem-inhabiting Ants in Switzerland-! — Rob. Stager has made a 

 study of species of Leptothorax, Cremastogaster, Colobopsis, Dolichoderus 

 which nest in hollow stems of bramble. Some were found in branches 

 of spruce, oak, Eumex, etc. The borings which the ants utilize are in 

 many cases made by wasps and bees. 



Development of Trichogramma evanescensWestw.§ — J.B, Gatenby 

 describes the embryonic development of Trichogramma evanescens, a 

 parasitic member of the family Chalcididte, a numerous and interesting 



* Journ. Zool. Research, ii. (1917) pp. 1-16 (3 figs.). 



t Comptes Rendus, clxiv. (1917) pp. 448-50. ' 



1 Revue Suisse Zool., xxv. (1917) pp. 95-109. 



§ Quart. Journ. Micr. Sci., ii. (1917) pp. 149-87 (3 pis.). 



