September 21, 191 1] 



NATURE 



379 



agency. The reading in of ideas involving purpose or 

 forethought on the part of the plant has been so 

 extremely general in oecological description of flowers, 

 is so pleasing to the imagination, and proves so 

 popular and difficult to escape from in elementary 

 teaching, that a detailed analysis of such well-known 

 Brucifer types as Matthiola, Raphanus, Alyssum, 

 Aubrietia, &c, is particularly welcome. 



Thus, among Crucifers generally, (i) the claws of 

 the petals bend away from the lateral stamens as if 

 to leave definite " entrance-slits " to the assumed 

 nectar-containing pouches of the lateral sepals ; (2) the 

 anthers of the longer stamens are commonly twisted 

 on their filaments so as to face round towards the 

 adjacent lateral ones, as if with the intention of rub- 

 bing the entering proboscis of an insect; (3) the 

 edges of the filaments are frequently extended into 

 elaborate appendage-growths which are apparently in- 

 tended to guide the proboscis of the insect-visitor 

 exactly to the secreting surface. Such details are so 

 obviouslv included under the heading of special adap- 

 tations to secure insect-pollination that the question 

 of their actual origin demands most careful investiga- 

 tion. 



The object of Dr. Giinthart's work is to show 

 that practically all subsidiary details of special 

 mechanism and final adjustment may be traced back 

 to a few fundamental tendencies in the floral con- 

 struction, which, being given by phylogeny, work out 

 on simple mechanical lines the construction details 

 which are at first sight so purposeful. Such "active- 

 Bctors " in the case of the Cruciferous flower are 

 distinguished as : — 



1. The tendency of the floral receptacle to extend in 

 the transverse plane of the floral diagram, this factor 

 controlling the dorsiventral insertion of the petals, 

 the lateral apertures of the flower-tube, &c. 



2. A tendency for the median sepals and adjacent 

 parts to be " elevated " by a peculiar growth-extension 

 in the median plane of the receptacle, which is respon- 

 sible for " true " (primary) calyx-pouches and the in- 

 creasing restriction of the secreting surface to lateral 

 hollows. 



3. The transverse and longitudinal extension of the 

 ovuliferous region : the former phenomenon (Silicu- 

 loseae) still further exaggerating characters induced 

 by the original transverse construction. 



4. The mutual pressures between a closed calyx and 

 central ovary exerted on "passive " petals and stamens 

 leading to the production of rotated anthers and mar- 

 ginal extensions of the filaments. 



In tracing the elaborate mechanical connections of 

 these phenomena, however, the problem of their mean- 

 ing is admittedly only removed one step further back. 

 We still remain ignorant of the reasons for the initia- 

 tion of these "active" characters. Nor is there any 

 reason to believe that continued research will ever 

 satisfactorily solve all problems which stretch back 

 into the distant phylogeny of the group. Still, every 

 step cleared up is one gained, and the vague concep- 

 tion of intention is gradually replaced by the view 

 that from an initial tendency, itself probably induced 

 by some physical cause, certain mechanical results 

 NO. 2l86, VOL. 8/] 



will necessarily follow, which will in turn determine 

 the subsequent possibilities of the evolution of the 

 race. Further, the fundamental factors thus deduced 

 should give the key to the systematic arrangement of 

 the family. 



FACT AND FANCY IN DIETETICS. 

 " What Shall I Eat?": a Manual of Rational Feed- 

 ing. By Dr. F. X. Gouraud. With a Preface by 

 Prof. A. Gautier. Authorised English translation 

 by F. J. Rebman. Pp. xvi + 379. (London : 

 Rebman, Ltd. ; New York : Rebman Co., n.d.) 

 Price 6s. net. 



THERE appears to be a plethora of books on diet 

 just now, but the present volume does not reach 

 the same standard of excellence which is noticeable in 

 several other books on the subject recently reviewed in 

 these columns. 



Dr. Gouraud's work contains a certain amount of 

 useful information, it is true, but it is so interwoven 

 with speculations and contradictions that it is not 

 likely to prove useful either to specialists or to the 

 public at large. 



The preface tells us it is intended for the business 

 man and the educated housewife among others, but 

 we wonder what the average man of business would 

 make out of the following sentences : — 



" Endogenetic purin is produced by the rejection of 

 nuclein by the organism ; its percentage, though 

 variable in each individual, is a fixed quantity in each 

 individual. Exogenetic purin of alimentary origin 

 varies considerably according to diet, and may be 

 reduced to zero by a regimen entirely free of all 

 xanthic bodies." 



" Beef is a powerful factor in membral hyperacidity. 

 Its alimentary value, which depends almost wholly on 

 the percentage of fats present in it, is rather slight. 

 It takes only second place to butter, sugar, and rice. 

 Its sole merit from the alimentary standpoint can only 

 be that it supplies within a small compass a compara- 

 tively large amount of assimilable nitrogen." 



"The third nutritive element in milk is the carbo- 

 hydrates, i.e. lactose or milk sugar. This is a bihexose 

 well known for its diuretic properties which makes 

 the sugar in diabetics. Phosphorus is also abundant, 

 and is present chiefly in the shape of physiological 

 values well differentiated." 



Quotations such as the preceding could be multiplied 

 indefinitely. A physiologist will at once detect the 

 gross misstatements of fact; but the man in the street, 

 so far as he can make head or tail out of technical 

 language, will at any rate detect the want of logic 

 and of a knowledge of English composition. The 

 glossary at the end of the book will not help him much, 

 for we learn there that purins are unclean or poisonou ; 

 substances, that xanthin is a yellow colouring matter, 

 that steapsin is a diastasic ferment, that inosite is a 

 saccharine substance, that casein is a derived albumin, 

 that galactose is lactose, that ammonia contains 

 hydrogen atones, &c, &c. 



The translator does not in the greater number of 

 instances know the English equivalents for French 

 technical terms, or for the names of pathological condi- 

 tions. We select only one gem for special mention ; 

 we are told that milk is curdled by the pressure of the 



