A WEEKLY ILLUSTRATED JOURNAL OF SCIENCE. 



Of Nat 



" To the solid ground 

 trusts the mind which builds for aye.' 



-Wordsworth. 



THURSDAY, JULY 6, 1911. 



CANCER AND ITS SUPPOSED CAUSES. 

 Induced Cell-Reproduction and Cancer. The Isolation 

 of the Chemical Causes of Normal and of Aug- 

 mented Asymmetrical Human Cell-Division. By 

 H. C. Ross. Being the results of researches carried 

 out by the author, with the assistance of J. W. 

 Cropper. Pp. xxviii + jgi. (London: John Mur- 

 ray, 1910.) Price 12s. net. 



MR. ROSS may be congratulated on having 

 written a book singularly unlike most sober 

 scientific treatises. He has been continually on the 

 track of new things, and even the frontispiece, pur- 

 porting- to portray photographically a mitotic figure 

 induced in a large lymphocyte, seems to have been 

 inserted in order to embody a fresh discovery made 

 after the rest of the book had gone to press, though 

 whether others will attach the same significance to the 

 photograph that Mr. Ross himself appears to do, the 

 future will doubtless decide. 



The book is written in an interesting and somewhat 

 journalistic style, and the preface contains excellent 

 autobiographical material designed, inter alia, to show 

 how " a new method of experimentation with indi- 

 vidual living human cells " was accidentally lighted 

 on by the author. 



Briefly, the method in question consists in concoct- 

 ing a jelly with agar, to which certain substances, 

 including a dye, are added. Upon this jelly, films of 

 blood containing living leucocytes are spread, which 

 can thus be examined microscopically under various 

 conditions. Ingenious devices for rapid photography 

 are described, and considerable use is made of the 

 photographs so taken in recording the results of 

 observation. 



A cytologist will find he has fallen into a rather 

 strange environment when he gets immersed in Mr. 

 Ross's book. He will have much to unlearn, and 

 many new facts to assimilate, before he can hope to 

 emulate the confident progress of his new leader. He 

 will have to recognise that "the word ' nucleus ' has 

 a very vague meaning " ; that chromosomes are not 

 NO. 2175, VOL. 87] 



really of nuclear origin, but that they originate from 

 the Altmann granules, and are formed in the cyto- 

 plasm ; that the nucleus forms the spindle and 

 the nucleolus constitutes the centrosomic appa- 

 ratus. He will probably also be astonished to 

 hear that living cells have not hitherto been 

 studied, and consequently that his own reminiscences 

 of observations on Ascaris and many other animals' 

 eggs, to say nothing of plants, in all of which he will 

 seem to remember that nuclear divisions have been 

 followed in the living cell, must be founded on delu- 

 sion. The zoological investigator will further discover 

 that he owes a larger debt than he was aware of to 

 his botanical colleagues, for Mr. Ross tells us that 

 "most cytological research has been carried out with 

 plant-cells." 



Mr. Ross thinks that " from the persistent examina- 

 tion of dead structures, cytology has been rather led 

 awav into a maze, from which it will be difficult to 

 extricate it." The main task which he sets him- 

 self in his book is to perform this service of extrication 

 and to show what can be accomplished by the study 

 of the living cell in ascertaining the causes which 

 underlie cell division, and especially of cell prolifera- 

 tion. The latter process is obviously of special im- 

 portance, inasmuch as it lies at the root, not only of 

 the ordinary processes of healing, but also, when it 

 assumes an aberrant character, of malignant disease 

 as well. 



The new engine of research, the jelly method, is 

 fully described, and one of the main objects in its use 

 by the author was to control the rate of diffusion of 

 different substances into the cell. There is an ex- 

 cursus on the problem of diffusion, and the net out- 

 come is embodied in formula? for making what Mr. 

 Ross terms "coefficient" jelly, meaning thereby a 

 jelly in which the rate of diffusion of stain, &c, can 

 be related to a standard in which a particular rate 

 is accepted as unity. 



This jelly is made up of a 2 per cent, solution of 

 agar, to which certain proportions ("units") of alkalis, 

 salts, stains (commonly Unna's polychrome methylene 

 blue), and other substances are respectively added. The 

 " units " of each ingredient are so fixed that a doubling 



B 



