56 



SQMMAKY OF CURKENT KESEAKGHES DELATING TO 



system is an oval, slightly irregular mass lying about the centre of the 

 body ; it was called a viscus or stomach liy Holcomb. The excretory 

 pores are located on eacii side of the body near the posterior end. 

 Four large flame cells are present. In cross-section the larva is round, 

 but the cephalic glands lie nearer one surface of the body, while the 

 central nervous body and ruilimentary digestive sac lie nearer the other. 

 These surfaces may be called respectively glandular and neural. The 

 ^gg and miracidiun) of S. japoiiicmn are smaller than those of *S'. mansoni 

 or S. hsematobium. The spine may be absent in as many as 50 p.c. 



ht 



ey.p 



]\Iiracidium of S. japonicum within the egg, from glandular surface ; 

 ap, anterior papilla ; rn', rudimentary digestive sac ; ad, anterior duCt ; 

 eg, cephalic gland ; /, flame cell ; c, capillary from flame cell ; ht, bladder 

 tubule ; .cx"p, excretory pore ; vm, vitelline membrane. Five germ cells 

 are shown. 



of specimens of eggs from one and the same case of .bipanese schisto- 

 somiasis. The egg-shell begins to swell soon after thc^ egg is placed 

 ill water, and it bursts by spUtting because of the swelling. The freed 

 miracidium differs in many details, e.g. the proportionately smaller 

 cephalic glands, from that of S. mansoni. Some good figures are 

 given. " J: A. T. 



Development of Digenic Trematodes and the Continuity of the 

 Germ Plasm. — L. Kathakixer {ZuoJ. Anzen/., 192U, 5., 2:^0-3). 

 From the fertilized ovum is formed the somatic tissue of the m.:-acidium 



