212 NATURAL SCIENCE. Sept., 



the new and full-bodied wine of modern biology. Consider Mr. 

 Thomson's 820 pages, which will be absorbed, index and all, by many 

 a gallant young Scot. Are you interested in karyokinesis and polar 

 bodies ? You will find an account of them here. Do problems of 

 heredity absorb you ? Here is Mr. Thomson with a table telling you 

 what is to be inherited and what not ; with an excursus upon germ- 

 tracks and the early separation of sexual cells. Perhaps the origin of 

 sex itself troubles your waking hours ? Mr. Thomson presents you 

 with a pemmican of himself and Professor Geddes. You are a student 

 of variation ? Mr. Thomson has a table for you. Or an organic 

 chemist ? Read Mr. Thomson upon Lipochrome and Zoonerythrin. 

 Or, excited by the " Challenger " number of Natural Science, you 

 would know about Plankton and Nekton ? Mr. Thomson has 

 discussions and diagrams, admirable and up-to-date. Or is it the 

 grander problems of evolution ? Consult the last chapter and bend 

 over the many-twigged tree on page 2. Would you know about 

 physiology ? Here is one whole chapter and a half chapter on that 

 neglected subject. Comparative Physiology. Are you a pathologist ? 

 Mr. Thomson is ready for you with half a chapter. And the 

 whole book deals with comparative anatomy and embryology, not 

 omitting the relations of Rhahdopleura and Cephalodisciis, the relation of 

 ganoids to teleosteans, the morphology of the auditory ossicles, the 

 pedigree of ccelenterata, the nephridia of amphioxus, the larval 

 twisting of the same animal, the pineal eye and the homologies of the 

 cranial nerves. 



Frankly, the thing is impossible. It would take not 820 pages 

 but 820 volumes to deal with the mass of subject-matter represented 

 in Mr. Thomson's book. It could have been written only by one of 

 great knowledge and greater diligence : by one who has consulted the 

 works of John Hunter and the latest issue of the Jahresbericht. But 

 we would willingly take it for granted that Mr. Thomson knows more 

 than any Scotch professor, or, for the matter of that, than any English, 

 German, French, or Dutch professor, and we would have from his 

 charming and luminous pen a volume of which the contents were 

 more congruous with the bulk. P. C. M. 



African Diseases. 

 On the Geographical Distribution of Tropical Diseases in Africa. By 

 R. W. Felkin. 8vo. Pp. 79, with folding table and map. Edinburgh: W. F. 

 Clay. 1895. Price 3s. 6d. nett. 



African diseases are now acquiring a somewhat extensive literature, 

 which is, unfortunately, often as irritating as the diseases themselves. 

 From Dr. Felkin we had expected something much better than the 

 average, for he is a lecturer on tropical diseases at the Medical 

 School of Edinburgh, and has had great experience and done most 

 useful work in Equatorial Africa. There is, of course, no comparison 

 between his book andj such a production as Pere Etterle's " Les 

 Maladies de I'Afrique Tropicale " ; but still many unfortunate errors 

 occur in it. Thus we are told that " the rainfall at the equator is 

 pretty evenly distributed throughout the year," which is certainly not 

 the case except locally ; then the author informs us that the 

 vegetation becomes generally richer, proceeding from west to east, 

 which is, perhaps, a misprint for vice versa. On p. 63 the Leprosy 

 Commission is reported to have cor^cluded that leprosy is neither con- 

 tagious nor hereditary. On p. 78 the Cape is said to be free from 

 malaria, and is so coloured on the map ; whereas malaria of a very 

 bad type is prevalent in some places, as at the back of Port Elizabeth. 



