9 



the specimen informed him that the stem of the plant 

 was likewise covered, and that he was disposed to think 

 this might be the cause of the " potato disease." The 

 late Dr. T. W. Harris believed the malady to be caused 

 by parasitic fungi. Dr. C. T. Jackson was of the same 

 opinion as Dr. Harris, and he supposed the presence of 

 the insect in this case to be purely accidental. 



Messrs. F. W. Putnam, J. L. Hun ne well, and J. M. 

 Hayward were elected Resident Members. 



July 16, 1856. 

 The President in the Chair. 



Prof. Agassiz stated that, a few years since he had described 

 a new family of fishes, Emhiotocoidce, in which the mode of re- 

 production is viviparous. He had now to announce the fact, 

 that, in another family, and one well known, there is likewise 

 viviparous reproduction. He had recently been examining the 

 ovary of the common haddock, and had found the ova already 

 passed the stages of segmentation. He had not yet been able to 

 examine them during the latest periods of development, but he 

 had no doubt that the embryos were developed within the ovary. 

 He thought, however, that the young might be brought forth in 

 some kind of an envelop, and thus escape observation. In the 

 Cod, Whiting, and American Hake, the ova likewise undergo 

 development in the ovary. Prof. Agassiz was informed by the 

 fisherman who had supplied him with the specimens in which 

 this discovery was made, that he had for a long time supposed 

 that the young were formed in the parent. 



Prof. Agassiz had been endeavoring to find homologies of 

 development in all animals of the vertebrated type, and had 



