156 ])R. EBERHARD, ON SEXUAL REPRODUCTION. 



tomatous opening. The embryos were dispersed pretty 

 uniformly throughout the entire parenchyma, and most of 

 them closely embraced by the parenchyma, and were 

 quiescent, whilst others had hollowed out, as it were, the 

 surrounding substance, and moved about actively, and 

 around their own axes, in the watery fluid. The parent 

 animal always had a strap-shaped nucleus, but which was 

 not always as large as in the ordinary individuals. The em- 

 bryos were oval or obovate, and uniformly rounded, and 

 beset with short, delicate cilia. At the anterior extremity 

 they appeared to Stein to be furnished with a small tubular 

 process, which he looked upon as a csecal suctorial disc. At 

 the posterior end was situated a minute, round, contractile 

 vesicle, and in the middle of the body a spherical or elon- 

 gated nucleus. The embryos certainly had no tentaculiform 

 processes, such as are commonly observed in the embryos of 

 other Infusoria. No conjugation of the mature animals was 

 ever witnessed. 



The above is a summary of Stein's observations, and the 

 author proceeds to describe his own. In a series of glasses 

 containing Lemna nmior', for the most part in a state of 

 decay, he was furnished with an abiindant supply of Bur- 

 saria truncatella. At the end of a few days, to his great 

 astonishment, he noticed that all the animalcules were filled, 

 and some of them even crammed with globular bodies of 

 uniform size. Some among them, in which the pei-istome was 

 almost entirely closed, resembled mere sacculi filled with 

 globules, so that it seemed as if the animalcules had surfeited 

 themselves with some kind of pollen, but that the process was 

 in reality one of reproduction was evident enough. He soon 

 remarked that some of the globules Avere protruded from 

 the still open slit in the parent body, but remained adherent to 

 its outer surface. After the disintegration of the parent — 

 which occurs so readily in this Infusorium — had taken place, 

 and the globular bodies had become liberated, the latter, 

 which were furnished with a contractile vesicle and spherical 

 nucleus, presented an AcinctnAxV^e form, whilst short tenta- 

 cles, Avith transf)arcnt nodular extremities, sprung up irregu- 

 larly, in greater or less number, all over the surface. These 

 tentacular processes, in several of the quiescent globules, 

 were seen to increase in size, and occasionally to attain such 

 a length that it would be difficult to distinguish them from 

 the sessile form of Podopkrya fixa. * Some of the more 

 mature globules, soon after their liberation, and often in the 

 course of a few minutes, became elongated, and assumed the 

 form of a somewhat flattened grain of wheat, including even 



