62 



NATURE 



[September 27, 1917 



Dr. Garnett, chairman of the council, has written 

 an interesting- " Foreword " to this book of reports. 

 He directs attention, among other things, to the 

 fact that in some of the most important schools 

 I boys on the classical side still learn no science, 



and to the statements in the report he adds the 

 remark that "the fate of a nation is not likely to 

 depend on the appreciation of music, art, or litera- 

 ture by its rulers, but it may well hang on their 

 appreciation of science." It is to be hoped that 

 the British people, who seem for the present to 

 be fairly well convinced of this truth, will act in 

 conformity with it in demanding that the Govern- 

 ment of the country shall no longer be officered 

 exclusively from non-scientific sources. 



These reports deal with a great variety of ques- 

 tions, among others with specialisation in schools 

 and universities. In universities the specialisa- 

 tion should not be carried to such an extent as to 

 sever all association with other studies, and 

 especially is it important that science students 

 should not abandon literary studies. Most 

 students, it may be supposed, would shrink from 

 doing so, if only for the sake of the mental refresh- 

 ment which comes from history, fiction, or poetry 

 in familiar use. 



The subject of examinations is dealt with in a 

 report all to itself. We do not now hear so much 

 from the few enthusiasts who, at one time, were 

 for doing away with examinations altogether. 

 The committee says that the evils arising from 

 examinations have been the subject of widespread 

 complaint for half a century. That is true, but it 

 is also shown that this is largely attributable to 

 abuse or defects of the system which admit of 

 remedy. And it is remarked that "in so far as 

 examinations check initiative, it should be noted 

 that candidates for professions whose Initiative 

 cannot survive the exact acquirement of the neces- 

 sary knowledge are not well fitted by nature for 

 such careers." The fact Is that where initiative 

 exists it will not be killed so easily. A comparison 

 was made a few years ago between the D.Sc. 's 

 of London University graduated under the original 

 system of pure examination and those who from 

 1887 onward obtained their degrees on presenta- 

 tion of a thesis and were practically exempt from 

 examination. Contrary to the expectations of 

 those who advocated the change, greatly increased 

 activity In the direction of research has not become 

 manifest as a consequence (see Nature for 

 November 3, 19 10, p. 30). W. A. T. 



EXPERIMENTAL EMBRYOLOGY. 



(i) Three Lectures on Experimental Embryology. 

 By Dr. J. W. Jenkinson. With a Biographical 

 Note by Dr. R. R. Marett. Pp. xvi+130. 

 (Oxford : At the Clarendon Press, 1917.) Price 

 75. 6d. net. 

 (2) L'CEuf et les Facteurs de I'OntogSnkse. Par 

 Prof. A. Brachet. Pp. vlii + 349 + xii. (Paris: 

 O. Doln et Fils, 1917.) Price 6 francs. 

 'T^HESE two volumes, although they deal with 

 -■- the same subject, are of very different char- 

 acter. Dr. Jenkinson 's work aims at being a con- 

 NO. 2500, VOL. 100] 1^ 



densed compendium of the most recent results ob- 

 tained in this division of zoology. Prof. Brachet 's 

 primer, on the other hand, gives a fascinating 

 account of the gradual building up of our know- 

 ledge of the mechanisms underlying the develop- 

 ment of the egg. He rigidly limits himself in 

 this case to the instances necessary to illustrate 

 his points. The substance of Dr. Jenkinson 's 

 book was delivered as three lectures in University 

 College, London, and all zoologists will be grate- 

 ful to Mrs. Jenkinson for publishing these lec- 

 tures. Dr. Jenkinson was one of the many 

 men of science who have sacrificed their 

 lives on behalf of their country, but in the 

 division of science which he represented his loss 

 was felt as a peculiarly cruel blow, for experi- 

 mental embryology has few representatives in 

 England, and amongst those few Dr. Jenkinson 

 was one of the most prominent. From the 

 account of his life by his friend. Dr. Marett, which 

 is contained in this volume, we learn that Dr. 

 Jenkinson began his career in the university by 

 the study of classics and of ancient philosophy, 

 and that he was drawn to the study of biology, not 

 primarily through the love of natural history, but 

 because he regarded the study of the laws of life 

 as the modern counterpart of the questions which 

 had occupied the minds of the ancient philosophers. 

 We can now understand a feature which puzzled 

 many admirers of Jenkinson's "Experimental 

 Embryology," published some years ago, viz. the 

 disproportionate space allotted to the discussion 

 of tlie views of Aristotle, a subject which to most 

 biologists has only a meagre academic Interest. 



The volume before us suffers somewhat 

 from being too much crammed with in- 

 sufficiently digested details to form a text- 

 book of the subject, and must be rather 

 regarded as a sequel to the " Experimental 

 Embryology " referred to above. The first lecture 

 gives a general sketch of some types of embryonic 

 development in order to illustrate the fact that 

 growth, cell-division, and differentiation are the 

 three cardinal facts in embryology which demand 

 explanation. In the discussion of growth Dr. 

 Jenkinson indicates his leaning towards Lceb's 

 theory that growth is due to a chemical reaction, 

 one of the products of which acts as a catalyser 

 to expedite the reaction. This theory, like so 

 many of Loeb's hypotheses, is at first sight attrac- 

 tive, but its entire value lies In its power to be 

 applied in detail. Loeb used it to explain the 

 supposed increase in nuclear matter, which he re- 

 garded as the most striking phenomenon of early 

 development, but he measured the increased quan- 

 tity of this material by counting the number of 

 nuclei without taking into account the fact that 

 the volume of the individual nucleus diminishes as 

 development proceeds. This point Is well brought 

 out in a series of figures which Dr. Jenkinson 

 gives. 



The second lecture deals with the question of 

 cleavage. A resume Is given of some of the 

 more striking results of separating individual 

 blastomeres from each other In different types of 

 egg and allowing them to develop Independently 



