Sgga and development of 



adult specimens rf 3ohinoB.tcraa revclutura found in 



~"**" 



the intestine of the ducV. .fc^rila m?.rila (Linn.)* about 

 forty -five mature eggs were obtained, nearly nil of which 

 Developed into rairaeidia* Prom adults of the s^iae species 

 raised experimentally in ducklings, several hundred eggs 



-v . C -U. C f 



were also obtained, part of which did not mature since they 

 were forced out by pressure from tae uterus. The eggs from 



both sources were ali>e in color, shape and aize variations 



IK*** V* 1 '- <;. w^ 



us vould be expected since the adults belong to ti.e 



specie They me-isurea in length frcm 0*094 to C.119 mm., 



C" I ''.'> ** 



the majority being about 0.108 mm* These figures fall within 

 ther-mge of variation given by Toons (1899 p. 679-689). Mia 

 measurements show larger and smaller eggs than mine, which 



is to be expected sin<je he /aeasured egj, from more adults. 



,5 ' * * 



The color of the egg is usually /ellow or yellowish brown. 



In order to watch the egg from day te day, they were 

 placed in Syracuse dinhes containing tap wgter. To ^eep the 

 eggs in a favorable medium part of the water was Ranged 

 daily. About fifteen egs were placed in each dish in a loom 



where the temperature varied little from 70 # 



r^ 9i < -" ' 



At one end of the egg is usually to be found a slight 

 thickening of the shell which appears of a darker color. At 

 the other end i the operoulum or cap* When th eggs emerge 

 from this echinostome t ey are in the one cell stage (fig* !) 

 This condition can also be readily determined by studying the 



eggs *hile atill in the uterus. /fl.though little wet* nan been do 



v> 



on echino storae eggs* it seems probable that the one cell stage 



