September 1, 1916] 



SCIENCE 



317 



found necessary to trace this fish back to 

 Aristotle, the Father of Natural History, with 

 the interesting result that it has become very 

 evident that Aristotle's Echeneis was not a 

 sucking-fish at all. 



The first reference in question is in the 

 "Natural History of Animals," Book II., 14; 

 505 h, 19-22; and, as rendered in Professor 

 D'Arcy W. Thompson's scholarly translation 

 (Oxford, 1910), it reads: 



Of fishes whose habitat is in the vicinity of rooks, 

 there is a tiny one, which some call the Echeneis 

 or shipholder. . . . Some people assert that it has 

 feet, but this is not the case: it appears, however, 

 to be furnished with feet from the fact that its 

 fins resemble these organs. 



A fair acquaintanceship with the sucking- 

 fish and a somewhat extensive reading of the 

 literature fail utterly to substantiate these! 

 statements. It is true that, blindly following 

 Aristotle, a number of the medieval writers on 

 natural history, or more properly pseudo-nat- 

 ural history, speak of the Echeneis as given to 

 laying fast hold on to rocks at the approach of 

 storms and staying there until the return of 

 fair weather. St. Ambrose in his "Hexa- 

 meron," written in the fourth century a.d., 

 seems to have been the first to set forth this 

 story of the Echeneis as a rock-holder and 

 weather prophet. However, this is plainly an 

 echo of Aristotle and there is no ground what- 

 ever, so far as I know, for any such belief, or 

 for thinking that it dwells among rocks. 



Further, it is not a " tiny fish." Adult 

 Echeneises run in size from 15 to 36 inches, 

 and adult Remoras from 10 to 15 inches in 

 length. It might be well just here to state that 

 Bemora is not only the smaller of the sucking- 

 fishes, but is generally of a dark uniform brown 

 color. Echeneis, on the other hand, is not only 

 much larger, but is of a slaty-brown or black 

 color, and is easily recognized by the broad 

 black stripe edged with white extending from 

 the angle of the mouth back through the eye 

 along the mid-lateral line to the base of the 

 caudal fin. Both fishes have on the top of the 

 head and on the back-of-the-neck region a 

 haustellum or sucker made up of the modified 

 spinous dorsal fin. This sucker consists of a 



circumferential rampart of soft tissue form- 

 ing an ellipse divided into compartments by 

 numerous crosswise partitions and having a 

 single lengthwise partition running from end 

 to end in the longest diameter of the ellipse, 

 which is also the median dorsal line of the 

 fish. This sucker is under muscular control, 

 and when applied flat to an object and then 

 raised a partial vacuum is created and the 

 sucking-fish clings fast. 



Last of all, no sucking-fish has fins even 

 distantly approaching the form of feet, the 

 pectoral and pelvic fins being of the ordinary 

 teleostean type and showing no special modi- 

 fication whatever. Many authors have thought 

 that in this last sentence Aristotle was de- 

 scribing an Antennariid fish, of which the 

 Sargassum fish, Pterophryne histrio, not un- 

 common in our waters, is a good example. 

 Such fish have the pectoral fins modified to 

 form organs not superficially unlike a hand. 

 However, in endeavoring to identify Aristotle's 

 fish we must take into consideration his whole 

 description. His fish I believe to have been 

 a goby, for the following reasons : gobies are 

 " tiny fish which live among rocks," and which 

 have their pelvic fins united to form a cup- 

 like adhesive organ, which is placed on the 

 thorax, in order that they may adhere to the 

 rocks among which they live. 



In another place, however, Aristotle does 

 refer to a fish which in my judgment is an 

 Echeneis, or sucking-fish, though he does not 

 he writes : 



In the seas between Cyrene and Egypt there is 

 a fish that attends on the dolphin, which is called 

 the "dolphin's louse." This fish gets exceeding 

 fat from enjoying an abundance of food while the 

 dolphin is out in pursuit of its prey. 



This fish Professor Thompson identifies with 

 the pilot-fish, Naucrates ductor, which is repre- 

 sented in our Atlantic coastal waters by the 

 very beautiful little Carangid fish, Seriola 

 zonata. This " dolphin's louse," however, I 

 identify as the sucking-fish. The first evidence 

 to be presented is found in the context. This 

 last reference to Aristotle comes in a section 

 given over to a consideration of various suck- 

 ing parasitic insects, lice, ticks, fleas, etc., and 



