ON THE LIFE AND GROWTH OF NEMATOIDS. 73 



tation ? does there exist, as all geographers pretend, a relation 

 between the coloration of the river and the sea ? I can only 

 place these questions before other naturalists who may have 

 the opportunity of exploiting these interesting districts. 



Nouvelles Observations sur le developpement et la vie de Nema- 

 toides. Par MM. Ercolani et Louis Vella. (From the 

 Comptes Rendus, July 3, 1854.) 



1. The embryos of the ovaviparous Nematoid worms do not 

 attain a complete development (that is to say are not furnished 

 with reproductive organs) in the locality in which they are 

 deposited by their mother, however favoui'able the conditions 

 for their development may appear. The ova of the oviparous 

 Nematoid worms, as well as the embryos of the ovaviparous, 

 must quit the situation in which they have been deposited, and 

 live in a state of liberty during a certain period, for their com- 

 pletion on re-entering the bodies of animals. 



2. The ova of certain of the Nematoidea remain stationary 

 in the intestinal mucus of the animals in which they were 

 deposited by the parent ; the phases of the development of 

 these ova removed from the mucus ensue with great rapidity 

 immediately they are placed in water. 



3. The development of the ova of Stroiu/i/lus auricidaris 

 (Zeder) has been obtained with tolerable facility in from two 

 to five days, notwithstanding the complete state of putrefaction 

 into which the bodies of the parent worms had fallen, and 

 which had been collected at the same time. 



4. The embryos thus produced have lived for twenty days 

 in the water, but without growing or developing any repro- 

 ductive organs. 



5. Analogous Nematoid embryos are often presented in the 

 little puddles of water in places where fowls are kept, and the 

 excrements of domestic animals are collected. 



G, Certain Infusoria, referied by Ehrenberg and other natu- 

 ralists to the genera Vibrio and Anguilhda, are nothing but 

 nematoid worms in the embryonic condition ; some, in fact, 

 belonging without doubt to the genus Oxyuris. 



Such, adds the Reporter (Prince Bonaparte), are the conclu- 

 sions of an important memoir which the authors are hastening 

 to communicate to the Academy of Sciences. Naturalists, he 

 observes, will be struck by the analogy between the embryos 

 above adverted to, and other embryos commonly found in 

 stagnant waters, and which have been regarded as perfect 

 animals. Rut how many of the putative genera of Infusoria, 

 he asks, should be eliminated from science? Should the 



