84 



NATURE 



[September 24, 1914 



a tenth of the time occupied by the method given 

 O" P' 37> while a candle is often easier to deal 

 with in experiments requiring heat than the 

 "brisk wood fire" advocated on p. 23. We 

 should like a prospector to take up this practical 

 little book after an elementary course in 

 mineralogy ; but this seems too much to ask of 

 those whose energy and observation may affect the 

 fortunes of huge companies. G. A. J. C. 



INSECTS AND DISEASE. 

 A Text-book of Medical Entomology. By Dr. 

 W. S. Patton and Dr. F. W. Cragg. Pp. 

 xxxiv + 768 + lxxxix plates. (London and 

 Madras : The Christian Literature Society for 

 India, 1913.) Price 15.12 rupees, or iZ. is. 



THE vast literature which has sprung up in 

 connection with medical entomology gives 

 some indication of the importance of this com- 

 paratively new subject, and the work under re- 

 view is the first attempt at a text-book. The 

 subject chiefly concerns those medical and 

 veterinary officers practising in the tropics, fre- 

 quently out of the reach of current literature, and 

 this book is designed to give to these men a 

 concise introduction to entomology in so far as it 

 is connected with medicine. 



The book is divided into twelve chapters, and 

 of these the first four, occupying rather more 

 than half the volume, deal with flies. The blood- 

 sucking and other noxious types of these insects 

 are dealt with very fully, and chapter ii., which 

 is entitled "Anatomy and Physiology of the 

 Blood-sucking Diptera," is perhaps the best in 

 the book. The different types of " biting " flies 

 are discussed as to general structure and internal 

 anatomy, and the question of the origin of the 

 mouth-parts of the "biting" from the "non- 

 biting " Muscidae is made an excuse for bringing 

 in an excellent description of the mouth-parts of 

 the house-fly. 



Chapters v. to x. deal with fleas, bugs, lice, 

 ticks, mites, and the pentastomids or "tongue 

 worms," the latter two groups, although not in- 

 sects, being usually regarded as coming within 

 the meaning of the term "entomology." 



The book is well illustrated, there being eighty- 

 nine plates, the majority of the figures being 

 original sketches by the wife of one of the 

 authors, and many of these indicate a large 

 amount of careful dissection. 



There are a few mistakes, such as that in bugs 

 the "mandibles are so opposed as to form a 

 channel with a circular lumen, while the maxillae 

 are armed with cutting teeth " (p. 6), and there 

 are occasionally definite statements made upon 

 NO. 2343, VOL. 94] 



debatable points, as with regard to the number 

 of segments composing the insect head (pp. 9 and 

 13); but the chief complaint we have to make is 

 against the way the book has been edited. There 

 are, for instance, some sentences which are either 

 difficult to understand or altogether unintelligible. 

 Thus, on p. 7 we read, " In the Diptera . . . the 

 sucking tube is formed by the outgrowth from the 

 pharynx of two spatulate slips, one dorsal and 

 the other ventral," and it is not until p. 21 that 

 we find the real meaning of this extraordinary 

 statement, where it is said, " In the Diptera [the 

 adaptation of the mouth for sucking] is accom- 

 plished by the development to a very high degree 

 of just those parts of the mouth apparatus which 

 are rudimentary in the cockroach, namely, the 

 epipharynx and the hypopharynx. These are out- 

 growths from the dorsal and ventral walls respec- 

 tively of the stomodaeum. ..." 



On p. 15 is the cryptic statement: "When the 

 head [of a fly] is viewed from behind the whole 

 of the posterior wall is seen to be chitinous, while 

 at the lower border there is a rounded foramen 

 between the anterior and posterior surfaces 

 through which the proboscis is protruded." 



Again, in various places we find references to 

 earlier passages which it is almost impossible to 

 trace. Thus, on p. 130, "The relations of the 

 haematocoele of the proboscis of the fly have been 

 described at some length in connection with the 

 mechanism of the mouth-parts." But there is no 

 section entitled " Mechanism of the mouth- 

 parts " ! There is a heading " Mechanism of the 

 proboscis," but the required statement is not 

 there, and it is only from three words in one 

 sentence that one gets a hint, and we ultimately 

 find what we want under " Movements of the 

 Labella " in connection with a description of the 

 proboscis of Musca (p. 46). 



One other complaint we make with regard to 

 the difficulty of using the book. In a number of 1 

 cases there is much lettering on the plates, and ! 

 there is the greatest difficulty in finding the ex- j 

 planatory pages. There is a page of reference 

 letters to cover plates i. to vii. immediately fol- 

 lowing plate i. and just before plate viii. is a page 

 to cover plates viii. to xiii, but there is nothing 

 on any of the plates to indicate v/here the explana- 

 tory pages are to be found. Unfortunately also 

 the page of reference letters for plates i. to vii. is 

 almost wholly wrong. 



There are thus many faults in the book, and 

 they are the more to be regretted since much of 

 the material is really first-class. It can only be 

 hoped that the work will run to a second edition 

 in which these defects can be remedied. 



Frank Balfour Browne. 



