24 



I could keep a given number in closed jars, where they were 

 perfectly still, from six to ten hours longer than in an open 

 Jar." 



Mr. Seal said : " How do you account for this i It is con- 

 trary to all we know concerning the diffusion of gases." 



Mr. Clark said : " It is a good deal like going back to 

 the old gravel methods. We can get better results with 

 gravel than on trays. After the eggs are advanced to a cer- 

 tain stage, they do as well on the trays as they do on the 

 gravel, but up to that time we get from five to twenty- five 

 per cent, better results on the gravel. What causes the 

 difference in the air-tight vessel and the open one I cannot 

 say," 



After the discussion the Chair announced that several 

 papers had been received from members who were unable 

 to attend the meeting. He asked that unanimous consent 

 be given to the Secretary to print them. This was given. 



On motion of Dr. Henshall, a vote of thanks was given 

 the Directors of the National Museum for their kindness 

 in allowing the Society the use of their lecture-room. 



The meeting then, on motion, adjourned sine die. 



EDWARD P. DOYLE, 



Recording Secretary. 



PART SECOND. 



ON THE TEETH OF FISHES AS A GUIDE TO THEIR 

 FOOD HABITS. 



By Dr. James A. Henshall. 



The food of fishes is either vegetable or animal, as in the 

 case of all other vertebrates. When vegetable, it, of 

 course, consists of aquatic plants and Alga., wliile the ani- 



