238 PROCEEDINGS OF THE AMERICAN ACADE5IY 



Professor Agassiz communicated a paper on Spermatozoa 

 by Dr. Burnet, of which he gave a brief abstract. He highly 

 commended the paper, as establishing new and important 

 views, and evincing uncommon qualifications on the part of 

 its author for such researches. 



On motion of Professor Agassiz, it was referred to the Com- 

 mittee of Publication. 



Professor Agassiz stated that he had ascertained that cat- 

 fishes, and the whole family of Siluridas, to which they belong, 

 have a sub-cutaneous cavity behind the humerus, and outside 

 of the peritoneum and the muscular walls of the abdomen, 

 into which protrude portions of the liver, and sometimes the 

 air-bladder and kidney. He also stated that these animals have 

 lateral holes for the admission of water into the interior of 

 their bodies. 



Professor Agassiz exhibited a part of the skin of a Bonito, 

 caught off Nahant, which presented a remarkable peculiarity 

 in the form of its scales. At first sight, the animal seemed to 

 offer the anomalous phenomenon of ctenoid and cycloid scales 

 occurring upon the same individual ; but, on further examina- 

 tion, the scales were found to be a new type, intermediate be- 

 tween the ctenoid and the cycloid, the serratures being merely 

 marginal, and not extending over the posterior surface. He 

 also called attention to some dark, longitudinal stripes, which 

 at first appeared to militate with the views he had brought 

 before the Academy at a late meeting, respecting the connec- 

 tion between the coloration and the structure of animals. On 

 examining them more carefully, however, each stripe was 

 found to originate at the base of one of the finlets of the 

 tail. 



Professor Agassiz, in reply to a question of the President, 

 stated that the shrill noise heard on suddenly drawing a cat- 

 fish out of the water is occasioned by the escape of air from 

 the air-bladder through the pharynx ; and, in reply to a re- 

 mark of Dr. Gould, he stated that a somewhat similar ex- 

 planation is applicable to the noise made by the drum-fish 



