50 RECORD OF CURRENT RESEARCHES RELATING TO 



of viyiparous or ovoviviparous amphibia and reptiles external to their 

 mother. lu June he opened a female Salamandra macidata, in which 

 he found fifteen ova, with embryos from 9 to 10 mm. long ; three of 

 these were placed in a cylindrical vessel, of about 300 cubic cm. 

 capacity, which contained a f per cent, solution of salt ; air was 

 passed through by Greiuer's apparatus. At first the embryos did well 

 and continued to develop, but the fluid was not sufficiently dense, 

 and it soon became evident that by osmosis the gelatinous covering 

 was becoming swollen out ; as a result, two eggs were one morning 

 found to be dying ; the third embryo lived for three weeks, and when 

 dead it was found to have increased to 12^ mm. in length ; the yolk 

 had been considerably used u\), and the eyes were distinctly pig- 

 mented. Similar experiments were made on the ova of Anguis 

 fragilis, but it was nut found possible to prevent osmosis and con- 

 sequent death, which is clearly due to the asphyxia resulting from the 

 vascular layer being withdrawn from the surface of tbe egg.* It is 

 to be hoped that a more useful fluid may soon bo found ; the amniotic 

 fluid is unfortunately very prone to putrefaction. 



Minute Structure of Cells, f — Impressed by the complexity of cell- 

 structure, Professor Julius Arnold has subjected to a critical examina- 

 tion the characters of (1) ganglion-cells, (2) smooth and striated 

 muscular fibres, (3) glandular, (4) hepatic, and (5) salivary gland 

 cells ; (6) epithelium, both that of the mucous membrane and that 

 which is ciliated ; (7) the lens which is stated to be a specially suitable 

 subject for examination, while (8) cartilage and (9) embryonic cells 

 are also studied. The author passes to certain pathological condi- 

 tions, of which he says that when their characters are compared with 

 those of normal tissues certain differences and certain resemblances 

 are found ; thus, in both cases, the filamentar structure is very much 

 the same, while in other points the abnormal cells give an indication 

 of the increase in them of the nutrient processes. In both normal and 

 pathological relations, cells possess a complicated structure ; the two 

 constituents, as ordinarily distinguished by us, the cell-body and the 

 cell-nucleus, consist of a ground-substance as well as of granules, 

 sets of granules, and filaments ; these latter may become very com- 

 plicated in the more highly developed forms of cells. He would 

 regard a cell as consisting of a nucleus and of an investing mass, 

 both of which contain in a homogeneous ground-substance granules 

 and filaments ; further observations are necessary before we can say 

 whether the names of parajtlasma and protoplasma as applied by 

 Kuppfer to the two constituent parts of a cell, are or are not justified 

 by morphological, genetic, and functional relations; but whatever 

 future results may lead to. Dr. Arnold has no doubt that they will 

 demonstrate that the structure of the cell is not so simple as it is 

 ordinarily considered to be. 



Nucleus in Cell-division.J— 111 discussing the changes undergone 

 by the nucleus in cell-division. Professor W. Flemming distinguishes 



* Cf. Note by M. Dare&te, ante, p. 19. 



t 'Aichiv path. Aiiat. u. Phys.' (Vhrhow), Ixxvii. (1879) p. 181. 



X Ibid., p. 1. 



