January 31, 1901] 



NA TURE 



323 



can scarcely refrain from saying that in the second part 

 of the work the author seems to have gone out of his 

 way to ignore some of the most peculiar, and therefore 

 the most instructive, types of reptile and fish life. 



As regards Part iii., which deals with invertebrates, we 

 feel ourselves less qualified to speak authoritatively either 

 in respect to the excellence of treatment or the reverse 

 on the part of the author, and therefore refrain from de- 

 tailed criticism. So far, however, as we can judge, the 

 classification adopted is, in some respects, less open to 

 objection than is that of the vertebrates. Even here, 

 however, the author gives opportunity for criticism in 

 many places. For example, among the molluscs no 

 mention is made of Dentalium, which most modern zoo- 

 logists regard as the representative of an ordei: by itself. 

 And it is scarcely consonant with the facts to say (p. 445) 

 that Ammonites " were animals similar to the nautilus in 

 all essentials of form and structure," unless, indeed, the 

 author attaches a very different meaning to the word 

 "essential " than we are disposed to assign to it. But 

 the most astounding feature in the whole book is the 

 total omission of the Brachiopods, the Tunicates, and the 

 Polyzoans I 



At the end of the work two pages are devoted to 

 geographical distribution. Here it will surprise many 

 zoologists to find the domesticated zebu given as one of 

 the characteristic animals of the Indian region, and "the 

 antelope " as one of those of Africa. Neither is it ap- 

 parent why the leopard and the pattther are included 

 among the characteristic mammals of Africa as distinct 

 from India. Again, the statement (p. 485) that "tracts 

 of land {e.f^. the Sahara) have been elevated out of the 

 ocean " may be cited as an extremely unfortunate one, 

 having regard to modern views as to the origin of deserts. 



If the editor in his preface is justified in his statement 

 that " the book is far superior in many respects to any 

 other elementary text-book of the subject known to me," 

 we may be permitted to add that in other respects it is 

 decidedly inferior to several works of the like nature that 

 could be named. R. L. 



OUR BOOK SHELF. 



The Mycetozoa and some Questions which they Suggest. 

 By the Right Hon. Sir Edward Fry, D.C.L., 

 LL.D., F.R.S., F.L S., and Agnes Fry. Pp. viii + 82. 

 (London : Knowledge Office, 1899.) 



"What's in a name?" Much, when it bars the way to 

 the knowledge of a group so rich in curious and beauti- 

 ful forms, and so important in the information that it can 

 afford upon the nature of protoplasm. The want of a 

 familiar name has led the authors to employ " myxies," 

 and the word may find acceptance, as it is not hard to 

 pronounce or remember, while it has the advantage of 

 leaving open the question of what their pets are. Though 

 generally reckoned now among plants, they are so 

 different from even the nearest groups that they may well 

 receive a neutral name. 



They have formed the subject of very excellent mono- 

 graphs in various languages, and to these the student 

 must turn who wishes to investigate the Mycetozoa 

 thoroughly. But the very excellence of these mono- 

 graphs renders them unsuitable to those that wish only 

 such a general outline as will place the group in true per- 

 spective in its relation to other low forms of living 



NO. 1 63 I, VOL. 63] 



beings, and will indicate its value in the study of living 

 protoplasm in simple organisms. There was room for a 

 small book that would give such an outline, and this 

 little work has been written to do so. One cannot read 

 it without recognising that it is the work of enthusiasts 

 whose aim is to communicate to others the pleasure 

 gained by themselves in the study. But no less evident 

 is the clearness of statement of the points of chief interest 

 resulting from width of view and facility of expression. 

 One can recognise that it is the work of amateurs by 

 occasional slips, as on p. 35, where it is stated that all 

 plants with a square stem and lipped flowers belong to 

 the family of the Labiatae. But such slips are few, and 

 no one can read the book without interest, while those 

 not already familiar with the Mycetozoa will have gained 

 as clear a conception of their nature and scientific interest 

 as can be acquired without actual personal study of these 

 organisms. The descriptions are supplemented by figures 

 admirably selected and executed. The book is one that 

 should induce those who read it to desire a fuller know- 

 ledge and to become students themselves. It will be 

 found an excellent introduction to the study of a most 

 interesting group. 



A School Chemistry. By Dr. John Waddell. Pp. 

 xiii + 278. (New York : The Macmillan Co., 1900.) 



Many text-books of physics and chemistry are now 

 constructed upon the interrogatory plan. Judiciously 

 used, the method has real educational advantages, for it 

 makes the student think for himself instead of merely 

 using his brain as an absorbing medium for what he 

 reads or is told. But the Socratic principle is often 

 overdone. The questions which a teacher asks — either 

 in book or verbally — in connection with experiments in 

 progress, are frequently not those which present them- 

 selves to the mind of the student. True, by suggesting 

 questions the pupil can be led to see the main points to 

 be brought out, and to have an interest in finding 

 answers to them ; but the ideal plan is to let his own 

 mind do the questioning instead of the mind of the 

 teacher. While, therefore, we agree that the interroga- 

 tive method largely employed by Dr. Waddell is often 

 stimulating, and certainly much better than the plan of 

 former text-books for schools, we do not believe it is 

 altogether satisfactory. 



Consider a boy in a laboratory, with Dr. Waddell's 

 book open at Experiments 9 and 10 (Chap. ii.). The 

 experiments are on the decomposition of water by 

 potassium and sodium, and will often result in accidents 

 unless performed under the eye of the teacher. But 

 leaving this out of account, let us see the questions 

 asked in the course of the description of Experiment 10 ; 

 they are as follows : " Does the potassium sink in the 

 water, or does it float ? What colour has the 

 flame ? . . . What shape does the sodium assume ? 

 Note how far it acts like potassium, and how far it 

 differs. Is there a flame ? Try the experiment with hot 

 water. . . . Why is there a flame in some cases with the 

 sodium and not with others ? What is the colour of the 

 flame ? Does sodium or potassium act the more violently 

 on water ? " Now a question we would ask is : How is 

 the pupil to give his answers? Is he supposed to write 

 a reply to each interrogation, or merely to make a mental 

 note of it? If the former, then the pupil must soon get 

 weary of the obstacles offered to the progress of his 

 practical work by the everlasting questions prompted, 

 not by his own curiosity, but by a book. In fact, we do 

 not believe it is possible to carry out the Socratic method 

 of science instruction successfully by means of a text- 

 book. The spirit of inquiry must come from within, or 

 be inspired by a teacher watching the progress of an 

 experiment. 



It must* not, however, be concluded from the foregoing 

 that Dr. Waddell's book is destitute of the elements cf 



