ZOOLOGY AND BOTANY, MICROSCOPY, ETC. (313 



tiation is not partial, but complete ; at least for the trunk-germs ; 

 Bergh has shown that the ten cells which appear during cleavage give 

 rise to them. Here again there is a distinction between pro- 

 visional and permanent epidermis, and the similarity to the Neiner- 

 tinea is due to the secondary union of the permanent ecto- and 

 mesoderm. 



The investigations which the author has been able to make into 

 the history of the development of the earthworm have shown him the 

 accuracy of many of Kleinenberg's statements, and have convinced 

 him that the trunk-germs of leeches are not, as is ordinarily supposed, 

 exactly homologous with the mesodermal stripes of Lumbricus, but 

 that the latter structures correspond to a part of what are contained 

 in the former. 



Structure of the Glandular Ventricle of Syllis.*— Mr. W. A. 

 Haswell prefers the term gizzard for that part of the digestive tract of 

 the Syllidaa which has been called glandular ventricle, for he finds 

 that there are no glands in the walls of this organ, but rather 

 muscles ; these have been supposed to be glands (possibly) because 

 they form hollow columns of striated muscle ; the transverse striaa 

 are better marked in some than in other species. As to the con- 

 stituent elements, it is found that they retain an embryonic structure 

 inasmuch as there is a polynucleated core ; this is of a red 

 colour in a fresh state, like nearly all the protoplasmic elements of 

 the body of the annelid. In one species the fibrils were seen to be 

 formed by the linear coalescence of rows of the large rounded 

 granules of which the main substance of the core is composed. 

 Mr. Haswell reminds us that hollow polynucleated fibres of striated 

 muscle-substance are found in various vertebrates, as an embryonic 

 condition of the solid fibres, and in certain insects and arachnids 

 as a permanent form. Simple (mononucleated) hollow fibres are 

 not unfrequently found in various Vermes, and are in some cases 

 transversely striated. 



Ovaries and Oviducts of Eudrilus.t — Mr. F. E. Beddard directs 

 attention to the fact that in a species of Eudrilus the oviduct is per- 

 fectly continuous with the ovary ; this is novel to the whole group of 

 Chsetopoda, and resembles the arrangement seen in Platyhelminths 

 and Hirudinea. 



New IchthyobdeHid.J — M. R. Saint-Loup describes a new form 

 of ichthyobdellid — Scorjpcenobdella elegans, which was found parasitic 

 on Scorpoena scrofa. It is 35 mm. long and 2 mm. wide behind the 

 oral sucker, and is of a brownish colour with black dots and larger 

 white patches. The walls of the body exhibit the typical hirudinid 

 arrangement, the digestive tube is remarkable for the absence of any 

 metameric divisions ; there are no lateral ramifications and no con 

 strictions ; there is a proboscis connected by two muscular bundles 

 with the walls of the body ; the posterior portion (cloaca) is remark- 



* Quart. Journ. Micr. Sci., xxvi. (1886) pp. 471-9 (1 pi.). 



t Zool. Anzeig., ix. (1886) pp. 342-4. 



j Comptes Rendus, cii. (1886) pp. 1180-3. 



