37 



oily fluid there may take place still other chemical processes, 

 efl^ected by difFerent conditions of the nervous system, such as 

 oxidation or deoxidation, we may explain in this way still other 

 changes^of color; for instance, from yellow, through red, to black ; 

 which, from observations made during the last winter, seems to 

 be really the case in certain turtles (^Emys picta and marginata). 



Mr. Charles J. Sprague exhibited specimens of the 

 Phallus duplicatus, Lin., in its immature as well as 

 mature condition, and read an account of its structure 

 and mode of growth. In conclusion, he remarked that 

 this fungus is not common, though it is found from time 

 to time after rains in shady places. Its odor is intolera- 

 bly strong and disagreeable ; but the strangeness as well 

 as beauty of its structure will repay an examination, 

 which may particularly offend the sense of smell. It is 

 common in Europe, and has been described and figured 

 by most of the writers upon Mycology. 



Prof. Agassiz remarked that he was not aware that this 

 fungus is rare in this country. He had observed it in 

 his garden at Cambridge. He thought the American 

 had a different shade of green from the European, though 

 this had not been noticed by Mr. Sprague. He had a 

 large specimen preserved in alcohol, which he should like 

 to compare with the European plant. 



Prof. Agassiz stated that Dr. Augustus Miiller had recently 

 pubHshed a paper on the Embryology of Petromyzon, (the 

 Lamprey,) presenting facts hardly to be credited if they had not 

 emanated from such authority. In the family of Cyclostome 

 Fishes, thei^e have been placed two characteristic genera, viz : 

 Petromyzon and Ammocetes. From the egg of Petromyzon, 

 Miiller says he has raised Ammocetes, and he has likewise seen 

 the latter become a Petromyzon. It is now well established, that 

 fishes undergo a form of metamorphosis as well as insects. Prof. 

 Agassiz had himself, within a few weeks, had an opportunity of 

 studying the embryology of a species of shark {Acantheus Ameri- 



