520 



Microscopical Essays. 



the plant are much more lively than thofe which are procured 

 from the dried grains. 



The principal phenomena of this kind of blighted wheat is 

 probably owing to thefe animalcula, who prevent the regular cir- 

 culation of the fap. They increafe in their fize in a certain pro- 

 portion to the plant, fo that at laft they may be obferved with 

 great eafe by the naked eye, being two-tenths of an inch long, 

 and nearly one-tenth in diameter. Fig. 4 reprefents one of thefe 

 magnified nearly in the fame proportion as Fig. 5 ; a a the ovary, 

 which may be traced almoft from the lower extremity to the mid- 

 dle of the' body, where the body becomes fo opake as to prevent 

 it's being feen any further. The eggs, when arrived at their full 

 growth, are nearly of a cylindric fhape, both ends rounded; 

 towards the extremity b there are two little protuberances d d, 

 through which the eggs are rood probably extruded ; thefe pro- 

 tuberances are not always vifib;e. The eggs are formed of a 

 fine tranfparent membrane ; it covers the young eel, which is 

 folded curioufly therein ; thefe eggs may often be found in the 

 plant. 



A moft fatisfaclory view of thefe eels is obtained by examin- 

 ing them with the folar microfcope ; it affords one of the moft 

 furprizing and magnificent fpe&ades ; two generations may be 

 often feen, one which draws near the allotted period of it's exift- 

 enCe, and another which only begins to enjoy the bleffings of 

 life. Some arrived at their full growth, others quite fmall, &c. 

 In fome we may perceive the young animalcula in motion in the 

 eggs, in others no fuch motion can be obferved ; with a variety 



of 



