1 62 



NATURE 



[April 8, 1920 



Arrhenius concerning- the acceleration by tem- 

 perature of the velocity of chemical reactions, and 

 the relation of this law to biological functions. 

 The author has carried out a large amount of 

 experimental work and correlated it with that of 

 others. 



There is an increase, an optimum, and a 

 decrease of many biological functions with tem- 

 perature, and in several cases the increase over 

 a certain rang-e is comparable with that of a 

 chemical reaction — e.g. the segmentation of an 

 ovum, the beat of the heart, or ferment action. 

 The reactions of the living- animal are, however, 

 too complicated to come under any simple law. 



A University Course in Botany. 



Botanical Memoirs. No. 4 : Elementary Notes on 

 Structural Botany. By A. H. Church. Pp. 27. 

 No. 5 : Elementary Notes on the Reproduction 

 of Angiosperms. By A. H. Church. Pp. 24. 

 (London : Oxford University Press, 1919-) 

 Price 25. net each. 



CONSIDERABLE interest has been shown 

 during- the past two years in the reconstruc- 

 tion of botanical teaching- at the universities, and 

 it seems opportune, therefore, that one of the 

 older universities should publish in some detail 

 the plan on which its instruction in botany is 

 based in so far as it relates to the elementary 

 courses in this subject. We gather from the con- 

 cluding note of Memoir 4 that the notes have 

 been written as schedules to accompany, and not 

 to replace, lectures, it being assumed tlTat the 

 lecturer can add explanatory emendations and 

 enlargements on special points. No doubt every 

 teacher will have his own views as to the arrange- 

 ment of the subject-matter of an elementary 

 course, and will desire to give special emphasis 

 to certain aspects, which he will do by the pro- 

 minence assigned to such parts of the subject. A 

 somewhat general feeling has been expressed in 

 the recent correspondence on botanical teaching 

 in the pages of the New Phytologist that 

 physiological botany has not always received 

 adequate attention or treatment in botanical 

 teaching. 



From that point of view it will be noted with 

 interest that the Oxford course of instruction 

 begins and ends in biological features, and is well 

 permeated with physiological considerations. On 

 the whole, however, it may be considered a 

 morphological treatment of the subject, as, indeed, 

 the title " Structural Botany " indicates, though 

 it is apparent that, as in most elementary courses, 

 structure is considered in the light of the functions 

 NO. 2632, VOL. 105] 



which the various organs have to perform. Occa- 

 sionally this mode of treatment might be more 

 closely adhered to. On p. 6, for instance, in 

 dealing with the stem of Helianthus, it is men- 

 tioned that the endodermis is "in this stem curi- 

 ously the only layer with starch," and no reason 

 for this phenomenon is advanced or even sug- 

 gested at this stage, though much later in the 

 course (p. 24) "falling starch" is referred to as 

 popular since 1900 as hypothesis of statocyte 

 nature. 



In connection with the palisade mesophyll no 

 allusion is made to the function of this tissue, nor 

 are any special reasons adduced for the shape 

 and arrangement of its cells. The same criticism 

 applies to the paragraph dealing with the spongy 

 mesophyll. The main criticism, however, which 

 anyone familiar with the difficulties of instructing 

 students within a severely limited time will level 

 against the course is that it attempts too much 

 within the period indicated by the author as avail- 

 able. Considerably shortened, the course might 

 gain in thoroughness of treatment what it would 

 lose in extensiveness. Interesting and enlighten- 

 ing, for example, as are the leaves of Ficus and 

 Nymphaea, the structure and function of a leaf 

 may be learnt from the cherry laurel alone. Simi- 

 larly in Memoir 5, some of the seeds mentioned, 

 like those of Aucuba, ^sculus, Juglans, and 

 Hedera, are not essential to the proper under- 

 standing of the structure of a seed in addition to 

 the two or three more common types. These are 

 only a few of many passages which might be 

 curtailed. No doubt the better plan would be to 

 retain the fuller course and to demand a 

 longer period for instruction, and we heartily 

 sympathise with the author's difficulties when re- 

 quired to supply what he calls "minimum 

 botany " for his students. Possibly under the 

 new regime at Oxford this may be remedied. If 

 the facts are as stated in the concluding paragraph 

 of Memoir 5, it is, as the author says, remarkable 

 that in a university, of primary importance the 

 teaching of plant biology should be of such a 

 meagre description. We fully share the author's 

 conviction that a knowledge of life in some form 

 should be part of the mental equipment of every 

 educated person. 



Recent Mathematical Text-books. 



(i) Unified Mathematics. By Prof. L. C. Kar- 

 pinski, Prof. Harry Y. Benedict, and Prof. 

 John W. Calhoun. Pp. viii4-522. (Boston, 

 New York, and Chicago : D. C. Heath and 

 Co. ; London : George G. Harrap and Co., Ltd., 

 1918.) Price I05. 6d. net. 



