June 15, 1905] 



NA TURE 



16: 



tained the centrosomes. That is, the attraction sphere 

 consists of the archoplasm plus the centrosomes. 



But during the prophase of the heterotype mitosis these 

 constituents become separated. The centrosomes are found 

 to lie outside of. and detached from, the archoplasm 

 (Fig. 3). At the same time the archoplasm itself under- 

 goes a change. It becomes vesiculated, and finally, at the 

 close of this cell generation, it is lost in the general cyto- 

 plasm of the daughter cells. 



In the prophase of the second maiotic division (homo- 

 type) the same phenomena recur. When the homotype 

 mitosis is over, the constituents of the sphere, or at least 

 some of them, enter into direct relation with parts of the 



. 4 and 5. — Later stages i 



Fig. 5. 

 I the development of the spermatid of r 



spermatozoon which arises by further differentiation of the 

 cell. As regards the archoplasm, it is again seen to con- 

 tain a number of minute vesicles which continue as before 

 to grow in size, whilst each contains a single refractive 

 and stainable granule (Fig. 3). Subsequently, several of 

 these vesicles fuse together, so that at a later stage in the 

 metamorphosis of the cell into a spermatozoon there only 

 remains a single large clear body, bounded by a distinct 

 membrane, containing in the centre one or more darkly 

 staining granules (Figs. 4, 5, 6). 



This body, originally described in iSqs as the archo- 

 plasmic vesicle, is a very conspicuous and apparently con- 

 stant feature peculiar to the spermatogenetic cells of, at 

 anv rate, the \'ertebrata, and it has since been encountered 

 beyond the limits of that group. 



NO. 1859, VOL. 72] 



Fig. 6. — Slightly later stage i 

 spermatid of man, witb ce 

 somes and tail. 



When fully developed it often assumes a size approxi- 

 mating to that of the nucleus. Indeed, the latter is often 

 deforined and made to assume a crescentic or ctvp-liUe 

 shape owing to the enlargement of the adjacent archo- 

 plasmic vesicle. The vesicle and its contents ultimately 

 form the so-called " cephalic cap " of the spermatozoon. 



The remarkable similarity between the structure just 

 described and those known as " Plimmcr's Bodies " will 

 have become obvious. It is not, perhaps, accidental that 

 just as in the case of nuclear divisions, so also in the 

 cellular inclusions, a parallelism between the cells of re- 

 productive tissues and of cancer cells should be found to 

 e.\ist. But the cells of cancer are not therefore regarded 

 as identical with those of the sexual cells, as was carefully 

 pointed out in the first communication of the authors in 

 iqo3. 



But the resemblances between what have been termed 

 gametoid and the true gametogenic cells now seem to 

 be even more significant than they appeared to be at that 

 time. Both classes of cells 

 are autonomous to a very ^ ■ -\ 



high degree, and both possess 



the faculty of continuous or , . ,- 



intermittent multiplication in- 

 dependently of the tissue re- 

 c|uirements of the organism. 

 .\nd finally, both exhibit 

 cellular and nuclear metamor- 

 phoses which not only, 

 mutatis mutandis, resemble 

 one another, but differ 

 materially from those pertain- 

 ing to the normal somatic 

 cells. 



It is possible that the malignant elements are the out- 

 come of a phylogenetic reversion, but the matter is obscured 

 by the disturbing influences that have been operative 

 during the actual ontogeny of the cells and tissues from 

 w'hich these elements have sprung. If this be so, the con- 

 nection apparent between gametoid and the true repro- 

 ductive cells will acquire a still deeper significance ; the 

 full discussion of this question is reserved for another 

 occasion. 



May 18. — " The .>\tomic Weight of Chlorine : an Attempt 

 to Determine the Equivalent of Chlorine by Direct Burning 

 with Hydrogen." By Prof. H. B. Dixon, F.R.S., and 



E. C. Edsar. 



In the w-hole of nine experiments described by the 

 authors 91786 grams of hydrogen combined with 3230403 

 grams of chlorine ; hence the equivalent weight of chlorine, 

 calculated in mass, is 35I05- 



The number obtained for the atomic weight of chlorine 

 is appreciably higher than that calculated by F. W. Clarke 

 from the previous determinations, and is slightly higher 

 than Stas's value : — 

 Clarke's calculation Stas Di.xon and Edga 



35"i79 •■ 35189 ■•■ 35 195 

 3S'447 •■■ 35 457 ••■ 35463 

 G. P. Baxter quotes the value 35-467 as being obtained 

 by Richards and Wells for the atomic weight of chlorine 

 — a number slightly higher than the authors'. 



Chemical Society, June i.— Prof. R. Meldola, F. RS., 

 president, in the chair. — The constituents of the seeds of 

 Hydnocarpus W'ightiana and of Hydnocarpus anthel- 

 miniica. Isolation of a homologue of chauhiioogric acid : 



F. B. Power and M. Barrowcliff. The authors found 

 that the oils of these two seeds very closely resemble 

 chaulmoogra oil, consisting chiefly of the glyceryl esters 

 of chaulmoogric acid and a lower homologue of the same 

 series, w^hich has the formula C,sH,jO„, and is designated 

 hydiwcarpic acid. The oil of Hydnocarpus Wightiana 

 appears to contain also a very small proportion of an acid 

 or acids belonging to the Hnolic or linolenic series. — The 

 constituents of the seeds of Gynocardia odorata : F. B. 

 Power and M. Barrowcliff. The oil expressed from 

 the seeds was found to consist of the glyceryl esters of 

 linolic acid or isomerides of the same series, palmitic acid, 

 linolenic and liolinolenic acids, and oleic acid. — The re- 

 lation of ammonium to the alkali metals. A study of 



11= I 

 = 16 



