492 



SCIENCE. 



[N. S. Vol. XVII. No. 430. 



reutly adaptive regenerative process of 

 high utility to the animal seems to require 

 for its explanation, in the female at least, 

 no special regulative factors that differ 

 from those concerned in the normal devel- 

 opment. 



Instincts of the Lepidoptera: A. G. Mater, 

 Museum of the Brooklyn Institute of 

 Arts and Sciences. 



On the Color-patterns of Certain Bermuda 

 Fishes: G. L. Bristol, New York Uni- 

 versity. 



During the six seasons, June to August, 

 the writer has collected large numbers of 

 living fishes in Bermuda and sent them to 

 the New York Aquarium, where they have 

 been placed on exhibition, and has made 

 many observations upon them in their nat- 

 ural surroundings and in confinement. 

 Taken together they comprise the principal 

 fishes of the West Indies and are fairly 

 representative of the coral-reef fishes. The 

 following conclusions are preliminary only, 

 and may serve only as a starting point for 

 more extended study. 



Three factors are correlated with the 

 habits to produce the specific appearance 

 of the various species. 



In general, (a) the scale of coloration is 

 high, (&) the patterns range from simple 

 to compex, and (c) the power to change 

 color varies from almost nil to an astonish- 

 ing degree. 



1. Warning Coloration. — Fishes with 

 high color, simple patterns and little if any 

 color-change are inedible, i. e., disagreeable, 

 or are covered with harsh scales and have 

 sharp fin rays. E. g., the green parrot fish, 

 the squirrel. 



2. Protective Coloration. — The scale of 

 coloration is not so high; the pattern is 

 complex and the color-change is great. 

 E. g., the 'four-eyed' fish {Chcetodon) , the 

 blue parrot, the hind. 



3. Midway between these is a third 

 group in which the three factors are more 

 nearly balanced -between the two extremes 

 and in which some offensive or defensive 

 device is added. The color is medium, 

 the pattern is not complex and the range 

 of color change is less than in the second 

 group. This group is illustrated by the 

 angel fish and the surgeons. 



Lymphatics of the Lung of Necturus: W. 



S. MiLLEE. 



The Brain of the Larva of Echinus escu- 

 lentus: E. W. MacBkide, McGill Uni- 

 versity. 



In larvEe of the common British sea- 

 urchin, Echinus esculentus, about the 

 twenty-first day after fertilization, there is 

 visible at the extreme front end of the 

 body a shallow pit lined by ectoderm cells 

 which are thicker than those covering the 

 general surface. When sections are made 

 through' the pit and examined with a 

 Zeiss apochromatic immersion lens, a very 

 thin layer of nervous fibrils is seen lying at 

 the base of the thickened ectoderm cells. 

 These fibrils are proved to be nervous by 

 the exact similarity in appearance and re- 

 action to osmic acid, between them and 

 the first fibrils which appear in the rudi- 

 ment of the adult nervous system. The 

 pit does not form a part of the longitudinal 

 ciliated band, and hence can not be com- 

 pared to the apical thickening observed by 

 Theel * in the larvse of Echinocyamus pusil- 

 lus, which becomes incorporated with the 

 ciliated band. It does, however, correspond 

 exactly in position with the thickening de- 

 scribed by Field t in the larva of Asteiias 

 vulgaris, and with the apical plate of neuro- 

 epithelium which is one of the character- 



* Th^el, ' The Development of Echinocyamus 

 pusillus,' Proc. Royal Soc. Vpsala, 1892. 



t Field, ' The Larva of Asterias vulgaris,' Quart. 

 Journ. Mier. So., 1891. 



