44 SUMMARY OF CURRENT RESEARCHES RELATING TO 



and filtered rain-water. On the following day, and notwithstanding 

 that all care had been taken to keep out germs from the air, Flagellata 

 exhibited themselves; soou afterwards there came Ciliata ; about two 

 months later Nauplius-like germs were detected, the number of which 

 rapidly increased, and later on they took on the form of Artemia 

 salina. The autlior points out that, in cases of this kind, death has 

 only been apparent ; organic combustion and nutritive changes have 

 not ceased entirely. 



A somewhat similar account is given of the rare rose-coloured 

 Infusorian Blepharisma. 



Vermes. 



Origin of the Central Nervous System of the Annelida.* — 

 Prof. N. Kleinenberg gives a summary of the results obtained by him 

 in studying the development of the Polycheeta, upon which he proposes 

 hereafter to publish a more extended memoir with figures. At present 

 he confines himself to making known the development of a single 

 species, the larva of Lo^padorhynchus, until its transformation into the 

 perfect animal. 



The most interesting point in the present communication is the 

 discovery of the circular nerve of the vibratile organ of the larva, and 

 the investigation of the development of the central nervous system of 

 the perfect animal. The author has found that during the trans- 

 formation of the larva into the perfect animal the circular nerve dis- 

 appears completely, together with the vibratile organ ; and the 

 rudiments of the typical central organs are not derived from the 

 transformation of the circular nerve, but originate from other parts of 

 the ectoderm. Consequently the nervous system of an Annelid is 

 not homologous with that of its larva. He thinks that the larvfe of 

 the Annelida possess only the central anterior nervous system of the 

 Coelenterata, but that the perfect animals have central organs proper 

 to them ; so that " the organ of the inferior type originates and 

 functions in the larva, but is eliminated and replaced by new forma- 

 tions in the adult animal." 



Swim-bladder-like Organs in Annelids.f — Dr. H. Eisig states that 

 in preserving specimens of Hesione sicula, he has often observed a 

 considerable number of air-bubbles escaping from the mouth or anus ; 

 by this and by the observation that in some cases specimens of the 

 same Annelid are found passively floating on the surface of the water 

 in which they were placed, he was led to the discovery that two con- 

 tractile appendages communicate with the intestine, and that these 

 must be regarded as the reservoirs of the gases ; according to their 

 condition they may appear as inconsiderable diverticula or as distinct 

 bladders ; he explains the fact of their being overlooked by previous 

 observers as due to their ordinarily empty condition after death. On 

 examining specimens of Syllis aurantiaca it was found that the so- 

 called T-shaped glands of the Syllidea are swim-bladders. 



* Atti R. Accad. Lincei, Transuuti, vi. (1881) p. 15. See Ann. and Mag 

 Nat. Hist, ix! (1882) p. 67. 



t MT. Zool. Stat. Neapel, ii. (1881) pp. 255-304 (3 pis.) 



