ZOOLOGY AND BOTANY, MICROSCOPY, ETC. dol 



contractile vacuoles. The aixthor adduces, from the discovery of this 

 organism, a fresh argument against drawing any sharp line between 

 the different sections of the Protista. 



Hsematozoa of Fishes.* — P. Mitrophanow gives some account of 

 new monadiform parasites in the blood of fishes, and discusses their 

 relations to the blood-corpuscles. He points out that, in consequence 

 of their having been looked upon as " curiosities," the literature that 

 deals with the presence of foreign organisms in the blood of healthy 

 animals is in a very fragmentary condition. The author has dis- 

 covered in the blood of Cohitis fossilis and of Carassius vulgaris an 

 organism which, at first sight, appeared to be a Nematode, but which 

 exhibited, on closer examination, no internal differentiation, and some 

 amoeboid characters. Of about 30-40 /jl long, it was only 1-1^ fx, 

 broad, and moved with great rapidity ; at its anterior end there was 

 a flagellum of considerable length, and the anterior was narrower 

 than the hinder end. When dying, or less active, the organism 

 became muchi shorter, and an undulating membrane became apparent. 

 The body of the organism, the membrane, and the flagellum, all ex- 

 hibited a homogeneous highly refractive protoplasm of great contrac- 

 tile power. Some striking varieties of this form are described. The 

 hsematozoon found in Carassius vulgaris was at first sight similar to 

 that found in C. fossilis, and just described, but it differed from it in 

 its somewhat larger size, and in the more distinct appearance of its 

 undulating membrane. For the reception of these forms a new genus 

 must be established which may be known as Hcematomonas, and the 

 two species as H. cohitis and H. carassii. After giving an exact 

 definition of these forms, the author proceeds to refer to the views of 

 Gaule, and states that he comes to the conclusion that he has here to 

 do with organisms, and not with the derivates of anatomical elements, 

 and he agrees with Prof. Pay Lankester that we have here Cytozoa. 

 In consequence of the paper of the last-mentioned naturalist,| he 

 feels it would be superfluous to discuss in detail his objections to 

 Gaule's views. 



BOTANY. 



A. GENERAL, including Embryology and Histology 

 of the PJianerogamia. 



Nature of the Process of Fertilization.J— E. Strasburger gives 

 a resume of the various modes in which the sexual elements, whether 

 " planogametes " or " aplanogametes," unite in various classes of 

 algae. He repeats his previously expressed view that impregnation 

 consists essentially in the union of the morphologically equivalent 

 parts of the two cells that unite. This union is, however, confined to 

 the cell-protoplasm and cell-nucleus, and does not extend to the chro- 



* Biol. Centralbl., iii. (1883) pp. 35-44. 



t See this Journnl, ii. (1882) p. 519. 



X Niederrhein. Ges. f. Natur- u. Heilkuude, Bonn, Dec. 4, 1882. 



