264 



SCIENCE 



[N. S. Vol. XXXI. No. 790 



just short of Kircher's clause in which he at- 

 tributes this theory to Mercurialis. 



Mercurialis, a celebrated Italian physician, 

 who lived from 1530 to 1607, was one of the 

 encyclopedic writers typical of the period. I 

 have searched the available volumes of his 

 works, including several editions of his ex- 

 tended treatise on the cause and nature of the 

 plague." So far I have failed to locate the 

 reference in question, but it is evident that 

 Kircher was indebted to Mercurialis for the 

 suggestion. 



The statement of Mercurialis can be re- 

 garded as no more than a lucky guess, but to 

 Kircher we must give more credit. This as- 

 tute Jesuit, born in 1601, was an indefatigable 

 worker, and his writings are much more than 

 mere compilations. There is no doubt that 

 long before Leeuwenhoek's discovery Kircher 

 had seen the larger species of bacteria, which 

 he described in the following words: 



It is known to all that decaying bodies abound 

 in worms, but not until after the wonderful in- 

 vention of the microscope was it found that all 

 putrid substances swarm with an innumerable 

 brood of worms which are imperceptible to the 

 naked eye, and I would never have believed it if 

 I had not proved it by frequent experiments, 

 during many years.' 



Among the substances in which he found 

 these " worms " he mentions spoiling meat, 

 cheese, milk, vinegar and decaying serpents. 

 He does not stop with the mere discovery, but 

 he attributes the production of disease to the 

 organisms, and formulates a theory of the 

 animate nature of contagion. Interpreted in 

 this light, the statement of Mercurialis as- 

 sumes a new dignity. The germ theory of 

 disease, which became dominant so soon after 

 this period, fell into disrepute, to be revivified 

 in the latter part of the nineteenth century. 

 Only now are we putting to the test the theory 



- " De pestelentia in universum, prcesertim vero 

 de Veneta et Patavina," Venice, 1577. 



'^ " Scrutinium Physico-medicum," 1658 ed., p. 

 42. This is one of many references which might 

 be cited. In his book " Ars magna lucis et umbrte," 

 published twelve years earlier, there is to be found 

 mention of these " worms," showing that Kireher's 

 observations really had extended over ".many 

 years." 



of Kircher relative to the role which flies play 

 in the dissemination of disease. 



Wm. a. Eiley 

 Cornell Ukiveesitt 



SCIENTIFIC BOOKS 

 A Treatise on Zoology. Part IX. (Oxford 



Zoological Series). Vertebrata Craniata. 



First Fascicle — Cyclostomes and Fishes. By 



E. S. Goodrich. London, Adam & Charles 



Black. 1909. Pp. 518, 515 figs. 



This is an advanced hand-book, scholarly in 

 treatment and brimful of facts, bringing up 

 to date the knowledge of a growing subject. 

 It embodies also a number of original results 

 which for the most part are based upon ana- 

 tomical data: its facts are marshalled con- 

 vincingly: many of its sections are admirably 

 treated, especially those on the theme of bone, 

 paired-fins and urogenital system. It consid- 

 ers fishes fossil as well as recent: its weakest 

 side is its treatment of the results of embry- 

 ology. The illustrations are numerous, usually 

 well selected, scores of them original and im- 

 portant. From the book-making standpoint, 

 the work is the equal of those which have pre- 

 ceded it in the Oxford series: among details 

 one may be mentioned which may seem trivial 

 to a strong-wristed reader — the paper, though 

 apparently heavy, does not weigh pounds as 

 in the case of several hand-books newly pub- 

 lished in the United States. 



Goodrich's book, in a word, is a very val- 

 uable contribution, and its preparation must 

 have proved a formidable task. Weak spots 

 it has, however, and reviewers will not fail to 

 discover them. The fact is one should hardly 

 expect that a single writer could follow the 

 literature of so broad a subject without an 

 occasional slip. As it is we may safely say 

 that Goodrich has accomplished a conspicu- 

 ously better task than any of his predecessors. 

 We may pass over proof errors, which are not 

 rare but of the usual type, and as we thumb 

 over the pages point out such defects as these : 

 " Myxinoids are normally hermaphrodite," 

 the author not knowing, apparently, that the 

 early findings in this matter are discredited. 

 Lcemargus, the great Greenland shark, does 

 not " fertilize the eggs externally " as Turner 



