INFUSORIA 437 



Meanwhile I will tell you the tragical and lamentable his- 

 tory of just such an embryo as this, that was eaten up 

 before it was born, under my own eye. One of the depre- 

 dators was a very amusing animalcule, which is sufficiently 

 scarce to make its occurrence a thing of interest, especially 

 to a young microscopist, as I was at the time. 



A large egg of (as I believe) Euchlanis dilatata had 

 been laid during the night on a leaf of Nitella, in the live- 

 box. When I observed it, the transparency of the shell 

 allowed the enclosed animal to be seen with its viscera; 

 which occasionally contracted and expanded; the place 

 of the mastax I could distinctly make out. The cilia were 

 vibrating, not very rapidly, but constantly, on the front, 

 where there was a vacant space between the animal and 

 the shell. From 7 A.M., when I first saw it, I watched 

 it for about eight hours, without perceiving any change; 

 but at that hour, having with- 

 drawn for a short time, I per- 

 ceived on my return that a 

 portion of the animal was out- 

 side the shell. The appear- 

 ance was that of a small col- 

 orless bladder oozing out at 

 an imperceptible aperture; and 

 this oval vesicle quickly but 

 gradually increased, until it COLEPS AND CHILOMONAS - 



was half as large as the egg itself. A little earlier than 

 this point, the cilia were seen on the front or lower side 

 of the excluded portion, and these began to wave lan- 

 guidly in a hooked form. They thus seemed much longer 

 and more substantial than when rotating in the perfect 

 animal. When excluded to the extent just named, some 



