i6 



measured .0139 inch in length, and the exuvia, in which it still 

 remained, .0227 of an inch. (See figure 3.) 



Exp. 22. Four of the embryos from the earthworm were 

 placed in one dram of egg albumen, after it was beaten to render 

 it fluid. They were placed in the incubator as before, and 

 changed to fresh albumen daily. After being kept in this wav 

 six and one-half days, they were alive, but there was no change 

 in their structure or size, or any appearance of moulting percept- 

 ible. Evidently the proper food for their metamorphosis and 

 growth was not contained in this fluid. In these culture exper- 

 iments the incubator used was one in which the heat could not 

 be thoroughly controlled. It is believed with a good one and 

 more experience better results could be attained. It is also 

 thought the blood serum of a fowl would be best adapted for 

 this purpose. This method of artificial culture of animal parasites 

 is believed to be new, and if varied according to the different 

 circumstances in which they are found in nature will, we think, 

 render easy the solution of some of the most difficult questions 

 as to the life history and embryonic forms of many of these 

 creatures. The subject is of great importance, for large num- 

 bers of both human beings and animals perish each year through 

 their agency. Moreover, it is not far removed from that great 

 question which occupies so prominent a position before the 

 medical profession at the present time. I refer to the germ the- 

 ory of disease. The one is an animal, the other a vegetable par- 

 asite. The method of artificial culture is now being used for 

 working out the latter; I see no reason why it cannot be success- 

 ful in the former. 



EMBRYOLOGY AND DEVELOPMENT OE SYNGAMUS. 



The egg is formed out of the granular material seen near the 

 extremity of the ovarian tubes. It is shaped into small round 

 bodies which pass down towards the uterus, within the horns of 

 which they are supposed to become impregnated, and receive the 

 hard external coat called the shell. Within the body of the female 

 Syngamus, about fourteen days after its entrance into the fowl, 

 are found several thousand eggs in various stages of develop- 

 ment, from the granular material of which they are formed, as 

 it exists in the ovaries and ovarian tubes, to the perfed egg in 

 the uterus. The perfect egg is oval, about .004 inch in its long, 



