3406 Microscopical Society. 



habits, and then entered more minutely into the description of their various organs, 

 viz., the trochal disk (which he stated to be wide and horse-shoe shaped, the edges 

 being richly provided with large cilia, presenting a very beautiful and wheel -like 

 movement), the mouth and its appendages, the oesophagus, and the intestines. He 

 next described the water vascular system, quoting at the same time the opinions of 

 various other observers upon this part of the subject. He next mentioned appear- 

 ances which he terms vacuolar thickenings, some of which he stated to have been con- 

 sidered by Prof. Ehrenberg as ganglia, others as testes, &c, but, in the author's 

 opinion, erroneously, inasmuch as they appear to him to be merely local thickenings 

 of the parietes in various parts of the body. The nervous system and organs of sense, 

 were then described ; and some remarks on the reproductive organs followed, in which 

 some curious observations on the development of the ova were given, showing that the 

 process is exactly that which takes place in all fecundated ova, and leading to the 

 supposition that Spermatozoa should, somewhere or other, be found. He, however, 

 had not been able to satisfy himself of their existence, although he had. seen objects 

 which answered precisely to Kollicher's description of the Spermatozoa in Megalo- 

 trocha, and expressed his opinion that it was impossible, in the present state of our 

 knowledge, to come to any definite conclusion upon the subject. He next proceeded 

 to make some remarks on the asexual propagation of Lacinularia and other Kotifera, 

 in which he pointed out the difference between the ordinary ova and those called 

 M winter ova," which last he proposed to call ephippial ova. The development and 

 progress of these last were very fully described ; and he concluded this part of the 

 subject by stating that " there are two kinds of reproductive bodies in Lacinularia 

 1. Bodies which resemble true ova in their origin and subsequent development, and 

 which possess only a single membrane ; 2. Bodies half as large again as the fore- 

 going, which resemble the ephippium of Daphnia, like it, have altogether three invest- 

 ments, and which do not resemble true ova, either in their origin or subsequent 

 development, which, therefore, probably do not require fecundation, and are thence to 

 be considered as a mode of asexual reproduction." He then proceeded to make some 

 remarks on the zoological position of the Rotifera, as deduced from the structure of 

 the Lacinularia, as now described ; and, after pointing out that the relations between 

 the Polyzoa and the Rotifera were at the best only mere analogies, he stated that the 

 general agreement in structure between the Rotifera and the Annuloidae (under which 

 term he includes the Annelida), the Echinoderms, the Trematodae, Turbellaria, and 

 Nematoidea) is very striking, and such as to constitute an unquestionable affinity. 

 This position he proved by numerous examples, and concluded by giving a sketch of 

 the affinities of the Annuloidae, in which class he proposes to place the Rotifera, thus 

 removing them entirely from the class Radiata of Cuvier, in which they have hitherto 

 been included. 



January 28, 1852. — Dr. Arthur Farre, President, in the chair. 

 The minutes of the preceding meeting were read and confirmed. 

 Two presents were announced, and the thanks of the Society voted to their re 

 spective donors. 



