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TJie Ohio Journal of Science [Vol. XVIII, No. 8, 



This hypertrophied tissue is developed principally at the 

 expense of the gonads of the host, (Plate III, Figs 1 and 2). 

 These are lacking or almost so in parasitized individuals. 

 The digestive system is also modified to some extent in that the 

 storage stomach is forced backwards and displaced by the 

 abnormal tissue. The malpighian tubules are much smaller in 

 parasitized individuals. Normally these are large and much 

 swollen, in parasitized specimens they are hardly enlarged at 



Text Fig. 5. Hypertrophied tissue in dryinized male Erythroneura comes 



(high power). 



all. When the parasite pushes apart the abdominal somites 

 and begins to grow outwards the cavity thus formed in the 

 body wall is enlarged until it becomes almost circular. Around 

 this cavity a layer of hypodermal cells is developed as an abortive 

 response by the host tissues to heal over the wound, (Plate IV, 

 Figs. 2 and 4). 



No other host was studied in as much detail in regard to 

 the cytological changes as was the above. However it is certain 

 that in the case of Gonatopus contortuliis parasitic on Delto- 

 cephalus sayi, (Plate VI, Fig. 2), there is no such development 

 and from general dissections of all the other species studied in 



