178 CARNEGIE INSTITUTION OF WASHINGTON. 



fishes has been made. These do not include even all the common forms and 

 comparatively little is known as yet concerning the conditions under which 

 they live, but a number of facts of considerable suggestive value have been 

 established. 



(1) Obliterative shading is obvious in all those species whose bodies are 

 cylindrical or fusiform, but is difficult to detect in angel fish and others 

 laterally so compressed that without evident counter-shading they seem flat 

 when seen in profile. Since it is difficult to avoid the conclusion that this 

 shading is the fundamental factor in conceaUng coloration, its very common 

 or universal occurrence among the reef fishes proves a serious obstacle in tlu; 

 way of any hypothesis which assigns warning value to their colors or color- 

 patterns. It renders equally improbable the idea that color and color- 

 I)atterns represent the result of some unknown internal activity, which has 

 produced an immunity type of coloration, because the reef fishes, on account 

 of habits or activity, are not subject to successful attacks of piscivorous 

 enemies. 



(2) Among the 30 species studied, there is no case in which any evident 

 reduction of defensive characters — scales, spines, teeth, etc. — is associated 

 with conspicuous color or combination of colors, as might be expected 

 upon the immunity hypothesis. Neither is there any consistent relation 

 between the presence of remarkably developed spines or teeth and types of 

 color or pattern which seem to be of a warning nature. The spotted moray, 

 one of the most voracious and pugnacious of the reef fishes, is mottled brown 

 and yellow. One of the surgeon fishes ( Teuthis hepatus) , armed with a lancet 

 upon either side of the caudal peduncle, may appear in a blue-black phase 

 or yellow-green, or may be as gray and inconspicuous as the gray snappers 

 with which it may frequently be seen swimming above the gray sand. 



(3) Upon the reef as a whole, browns and gray are the commonest colors. 

 However, the reefs and reef-flats are not in all parts equally frequented by 

 fish, so that relative frequency of colors can not be gaged sunply by deter- 

 mining the areas covered by gray sand, brown algse, etc. Upon those parts 

 of the Loggerhead reefs where fish are most abundant, the heads of Pontes 

 astrceoides, or rather the symbiotic algse associated with them, contribute 

 a very conspicuous yellow element to the environment in which the fish live. 



A rather rough analysis of the colors found upon the 30 species examined 

 has been made and the relative frequency in which the different colors 

 occur is as follows: Yellow, 19 times; brown and gray, 16 times each; blue, 

 8 times; red and green, 5 times each; and black, 3 times. I do not for a 

 moment advance the idea that colors occur upon the fish in the same pro- 

 portion as that in which they appear upon the reef, but suggest that the 

 facts above noted indicate a correspondence between reef and fish colors 

 which agrees more closely with the case of the Sargassum species than 

 might have been anticipated upon the hypothesis of immunity or of warning 

 color. 



Report upon Investigation of the Dimorphic Spermatozoa of Stromhus gigas, 

 by E. E. Reinke, Princeton University. 



The object of this investigation was to determine as far as possible what 

 physiological relation exists between the eupyrene (typical) and the apyrene 

 (atypical) spermatozoa of Stromhus. Twenty-five females which had copu- 

 lated were carefully dissected and the contents of the vagina, the uterus, 

 and the bursa seminalis were examined microscopically in order to ascertain 

 the fate of the two kinds of spermatozoa. In brief, it was conclusively 



