63 



nured with liquid taken directly from the vaults. Pie was not 

 aware, however, of the ova liaviug been found upon the plants. 



Dr. Weinland, in reply to a question as to the manner in 

 which these animals reach the brain and other organs, answered 

 that he had seen, in one instance, a passage through a membrane 

 without any trace being left in it ; and that it was not impossible 

 that penetration could be elFected thi'ough many tissues and to a 

 considerable distance. 



Prof. Agassiz remarked that, at a previous meeting, he 

 had stated that it would probably be found necessary to 

 divide what is now called the Class of Fishes into sev- 

 eral distinct classes. 



He could not yet say what position the Ganoids would take, — 

 whether that of a sepai'ate class or of an order ; — but it is certain 

 that they form a natural group. Stui-geons and gar-pikes belong 

 together, though they differ so much in external appearance ; and 

 Prof. Agassiz gave, as one of the points of resemblance serving 

 to unite the two, the manner of development of the scales. The 

 small gar-pikes, (^Lepidosteus,) recently exhibited by him, pre- 

 sented scales just beginning to form. In the youngest speci- 

 men thei'e was a row along the middle line of the body ; in 

 another, more advanced in age, there was a row of scales above 

 and below the median line also, where the scales first appear. 

 Towards the tail the scales were crowded together, and were of a 

 rhomboidal form, covering the posterior lobe of the body, and 

 extending to the fin rays. The same method of development 

 Prof. Agassiz had noticed in the sturgeon, and the same rhom- 

 boidal scales upon the tail. He expects to find the mouth be- 

 neath the snout in the embryo Lepidosteus, as it is in the stur- 

 geon, and still other coincidences in the embryonic form. 



The President inquired in what order the scales appear in 

 osseous fishes. 



Prof. Agassiz replied that he could not answer. He had seen 

 the scales in Salmonida3 extremely small, but never at a suffi- 

 ciently early period to determine the order of development. 



Mr. James E. Mills gave the results of an investigation 

 made under the direction of Prof. Agassiz, to determine 



