516 



University of California Puhlicafions in Zoology [Vol. 18 



the anterior ducts (fig. 6, ad) which open on each side of the body 

 between the so-called cephalic region and the body proper. The 

 internal relations of these ducts were not clear, but extrusion from 

 them of the oil globules was observed both in S. japonicum and S. 

 mansoni. Holcomb (1907, fig. 3) figures the anterior ducts in >S. 

 mansoni as if connected with the cephalic glands. My studies gave 

 no evidence of this relation. 



Fig. 6. Miracidium of S. japonicum within the Qgg, from glandular surface; 

 letters as in figures 2 and 4. The reference line from eg is incorrectly drawn. 

 It should be extended to the cephalic gland on the left side. 



The exact process of the hatching of the egg I did not follow, nor did 

 I see the miracidium escape. The remarkable microphotograph shown 

 in figure 5 was taken by Dr. J. P. Ilickey and I am much indebted 

 to him for its use. In the photograph the split through which the 

 miracidium has just escaped is across the end of the egg. The process 

 of hatching of the embryo from the egg has been described for 8. 

 haematohium by Seligmann (1898, pp. 386-388) and by Conor (1910, 

 p. 533). Smith (1911, p. 64) described this process for the egg of 

 S. japonicum. The accounts agree with my observations in that the 

 egg shell begins to swell soon after the egg is placed in water and 



