May 8, 1885.] 



SCIENCE. 



389 



on the effects of the application of stimulants 

 — mechanical, electrical, and chemical — are 

 described. The action of poisons upon jelly- 

 fishes shows a wonderful resemblance to that 

 of the same on higher animals. Many con- 

 clusive experiments are given to prove that 

 the fatal effects of transferring medusae from 

 salt to fresh water is not due to a difference in 

 density of the two media. A medusa arti- 

 ficially frozen into a solid block of ice, so that 

 ice-crystals are formed in its body, is not killed 

 by the operation. 



The observations on the star-fishes and sea- 

 urchins are recorded in a single chapter ; yet 

 they are in many respects as interesting as 

 those on the jelly-fishes in the preceding nine 

 chapters. The author points out the different 

 methods adopted by star-fishes and sea-urchins 

 in righting themselves when turned upon their 

 backs. The ' geometrical regularit}' ' of these 

 animals, in their nervous system as in their 

 form, leads to a " very pretty instance in 

 physiology of the physical principle of the 

 parallelogram of forces." If two stimuli are 

 applied simultaneously at opposite extremities 

 of an axis passing horizontally through a round 

 sea-urchin, the Echinus moves off 'ina direc- 

 tion at right angles ' to a line connecting these 

 points. 



The author finds, that, by cutting off the 

 eye-spots from several star-fishes and sea- 

 urchins, they do not seek the light thrown into 

 the dish, as is invariably their habit when these 

 organs are intact. He also finds that an ex- 

 cised ray of a star-fish makes its way to the 

 beam of light as if it were an entire animal. 

 A star-fish, with all the eye-spots but one re- 

 moved, crawls to the light. 



Romanes ascribes to the star-fish a sense of 

 smell from the following experiments : a star- 

 fish is kept fasting for several days. A piece 

 of shell-fish is then placed in the tank with the 

 animal. He immediately crawled toward it. 

 ''Moreover," says the author, " if a small piece 

 of the food were held in a pair of forceps, and 

 gentry withdrawn as the star-fish approached 

 it, the animal could be led about the floor of 

 the tank in any direction, just as a hungry dog 

 could be led about by continually withdrawing 

 from his nose a piece of meat as he continu- 

 ally follows it up." To determine the region 

 of the body where the supposed sense of smell 

 is located, the experimenter removed the eye- 

 spots, and the hungry star-fish moved in the 

 direction of its food. He varnished the whole 

 upper (aboral) surface of the bod} T , and still 

 the acuteness of the sense was not diminished. 

 He concludes that the sense is not localized, 



except that it is "distributed over the whole 

 of the ventral or lower surface of the animal." 



These last-mentioned experiments can be 

 easily tested by any one without elaborate ap- 

 paratus. Certainly one great value of all the 

 experiments is their great simplicity ; and the 

 book has this strong recommendation to con- 

 tribute to make it, what the author expresses 

 a wish that it should be, a "book of service 

 to the working plrysiologist." 



The work of Romanes is certainly one of the 

 most valuable contributions to the physiology 

 of the primitive nervous system which have been 

 published, and it is the only book on this sub- 

 ject which has yet appeared in America. Yet, 

 much as there is to praise in this book, there 

 are several statements which an anatomist can- 

 not accept ; but these do not detract from the 

 excellence of the work, as far as the main 

 questions are concerned. 



MINOR BOOK NOTICES. 



Professor Johnson's little book on curve- 

 tracing is more clearly arranged than Frost's 

 treatise, and seems much better suited to the 

 wants of readers who need only a general 

 knowledge of methods, and do not wish to go 

 into refinements of approximation which they 

 may seldom or never have occasion to use. 

 Students rarely think it, worth while to spend 

 much time in curve-tracing after they have once 

 acquired a little knowledge of analytic geome- 

 try ; but every man who means to devote his 

 attention specially to mathematics needs to 

 have some facility in interpreting equations geo- 

 metrically, and this he can best get by studying 

 some such book as the present one. Professor 

 Johnson treats the analytical triangle in a wa}' 

 which will recommend itself, we feel sure, to 

 mathematicians, and introduces it so early that 

 a person who has time for no more can read 

 the first half of the book to advantage. In a 

 few instances the addition of a short clause 

 would make clear sentences which are now 

 rather obscure. 



Pettit's little book gives in a concise form a 

 brief account of nearly all the more important 



Curve-tracing in cartesian co-ordinates. By "William 

 Woolsey Johnson, professor of mathematics at the U. S. naval 

 academy. New York, Wiley, 1884. 6+86 p. 16°. 



Modern reproductive graphic processes. Jambs S. Pettit. 

 New York, Van Nostrand, 1SS4. (Van Nostrand sc. ser., No. 

 76.) 4+127 p. 16°. 



Comparative physiology and psychology. A discussion of the 

 evolution and relations of the mind and body of man and ani- 

 mals. By S. V. Clevengek, M.D. Chicago, Jansen, Mcdurg, 

 &, Co., 1885. 6+247+10 p. 8°. 



Elements of zoology. By C. F. Holder and J. B. Holder, 

 M.D. New York, Appleton, 1884. (Appletou's sc. text-books.) 

 10+385 p., illustr. 8 4 . 



