UARDWICKE'S SCIENCE-GOSSIP. 



147 



XOTES ON NEW BOOKS. 



/SLAND LIFE, by Dr. A. R. Wallace 

 (Macmillan & Co.). We are delighted to 

 welcome a cheap edition of this noble and most 

 suggestive book. We know of nothing in natural 

 history literature to equal it, except Darwin's 

 classical Voyage of the Beagle. In its two volume 

 form, Mr. Wallace's splendid book was practically 

 unobtainable to naturalists, the most distinguished 

 of whom, are as a rule the poorest. Hence we 

 regard it as a real boon that Messrs. Macmillan, the 

 publishers, have now issued a cheaD edition of this 

 work which Dr. Wallace has taken considerable and 

 careful pains to bring up to date, so as to say the 

 latest words on the subject. 



On the Modification of Organisms, by David Syme, 

 (Melbourne : George Robertson & Co. London : 

 Kegan Paul, Trench & Co.). This is a difficult 

 book to notice. The author makes some clever 

 points, although his style is neither classical nor 

 attractive. He evidently thinks that Darwin knew 

 nothing about Darwinism, as will be seen by the 

 following quotation, which is on the fifteenth page of 

 the book. " Summary. — We have seen that Darwin's 

 language is wanting in precision, and his definitions 

 and theories are variable and contradictory. In one 

 place natural selection is the ' struggle for existence,' 

 in another, the ' struggle for existence ' is said to 

 ' bear on ' natural selection ; in a third place he 

 speaks of the ' struggle for existence, and natural 

 existence,' as if they were independent principles ; 

 in one place, again, he defines natural selection as 

 ' the survival of the fittest,' thus confounding cause 

 with effect, and in another place he says that natural 

 selection ' depends on ' the survival of the fittest ; 

 while to add to the confusion he tells us in another 

 place that ' the conditions of life include natural 

 selection,' inasmuch as they determine whether this 

 or that variety shall survive. In numerous places he 

 explains that the function of natural selection is 

 merely selective, as the term implies, that it operates 

 on variations which are provided for it, and is 

 absolutely powerless to effect anything without them ; 

 in other places he insists that variations are created 

 by natural selection, and that, in fact, every change 

 in structure and function is within the power of 

 natural selection." 



Laboratory Practice ; a series of Experiments on the 

 Fundamental Principles of Chemistry, by Josiah 

 Parsons Cooke, LL.D., (London : Kegan Paul, 

 Trench, Triibner & Co., Ltd.). It is a mighty jump 

 from 1874, when Dr. Cooke, the distinguished 

 American chemist wrote one of the most suggestive 

 volumes of the International Scientific Library series, 

 entitled " The New Chemistry." No other book has 

 done more since then to suggest new lines of thought 

 to thoughtful chemistry students. It is therefore with 

 sincerest pleasure we draw our readers' attention to 



this practically valuable book. Its aim and scope 

 will be best gathered from the following quotation 

 from the introduction. "The educational value of 

 such a course as is here outlined, depends entirely on 

 the manner in which the work is directed and super- 

 vised. The student should be instructed, by con- 

 tinued reiteration, if necessary, I. To observe the 

 minutest particular in regard to every experiment. 

 2. To distinguish essential from non-essential 

 phenomena. 3. To draw correct inferences from the 

 results. 4. To express concisely but clearly in writ- 

 ing the facts observed and conclusions reached." 



Mineralogy, by Frederick H. Hatch, Ph.D., 

 F.G.S., (London : Whittaker & Co.). We cordially 

 recommend this cheap little book of Dr. Hatch's as 

 one of the best that students could purchase. It is 

 abundantly illustrated, and Dr. Hatch is one of the 

 few scientific teachers who possess the gift of 

 lucidity. 



Tlieorelical Mechanics, Elementary Stage, by J. 

 Spencer, B.Sc, etc. (London : Percival & Co.). Mr. 

 Spencer is one of our most active workers in educa- 

 tional science, but we are sorry to find it necessary, 

 and that the science and art department of South 

 Kensington is constantly requiring such hosts of 

 victims, under the title of preparatory books. How- 

 ever, if students require a cheap and good manual on 

 Theoretical Mechanics, they cannot do better than 

 get the one above referred to. 



Farmyard Manure, its nature, composition, and' 

 treatment, by C. M. Aikman, M.A., etc. (London : 

 William Blackwood & Sons). We think Prof. 

 Aikman has done perfectly right in publishing this 

 little brochure, which is in substance a chapter from 

 the larger work he is preparing on soils and manures. 



NOTES ON THE INFUSORIA. 



By Bernard Thomas. 



V. — Heterotrichous Ciliata. 



IN this group some of the cilia are modified into 

 hooks, styles or bristles, and are unevenly dis- 

 tributed over the body. 



24. Coleps hirtus (Fig. 87), is about the five hun- 

 dredth of an inch long. It is often found feeding on 

 dead Entomostraca. Unlike the preceding ciliata, it 

 is symmetrical ; that is, the body might be divided 

 by a longitudinal line into two halves. Another 

 peculiarity of Coleps is the possession of a chitinous 

 cell-wall, which can be seen separated from the 

 protoplasm during division (Fig. 87, 3). In shape 

 Coleps is oval, rounded behind, more truncate in 

 front ; sometimes it is somewhat pear-shaped, 

 (Fig. 87, 2) at others separated into two halves by a 

 more or less deep transverse constriction (Fig. 87). 



The cell-wall is marked by strong longitudinal 

 and transverse grooves, which go from end to end and 



11 2 



