REVIEWS 697 



Types of Floral Mechanism. By Arthur H. Church, M.A., D.Sc. Parti. 

 Types i.-xii. (January to April). [Pp. vii. + 2ii.] (Oxford : at the Clarendon 

 Press, 1908. £1 is. net.) 



The Oxford University Press, to which botanists for many years have been very 

 deeply indebted for its enterprise in publishing, amongst other volumes, the well- 

 known series of scholarly translations of botanical classics, has earned their further 

 gratitude by issuing this, without doubt one of the most interesting botanical books 

 of recent years, and one which in its turn should become a classic. On first turn- 

 ing over the pages cne is filled with admiration of a great work of art. The size, 

 royal quarto, the beauty and close adherence to nature of the thirty-nine coloured 

 plates, the delicacy and accuracy of the very numerous other plates and illustrations 

 in the text, the clearness of the typography, all combine to render the mere casual 

 examination a deep and lasting pleasure. To the better type of student the book 

 must serve as a valuable stimulus, although the modest remark of the author in 

 his introduction that " all figures are drawn in the size and style and of the character 

 to be expected of good-class student work " might well inculcate a feeling akin to 

 despair in those not naturally endowed with the gift of draughtsmanship so richly 

 bestowed upon Dr. Church. 



The aim and scope of the book are sufficiently indicated in the sub-title : "A 

 selection of diagrams and descriptions of common flowers arranged as an intro- 

 duction to the systematic study of Angiosperms." Twelve types are nominally 

 dealt with, all spring flowers, but comparisons with allied forms are introduced 

 under each type, so that the actual number of plants described and discussed in 

 this part is actually but two short of fifty. 



An examination in more detail of the mode of treatment of one type, e.g. 

 Viola odorata and its congeners (pp. 88-117), will serve to indicate the wealth of 

 information the volume contains. After briefly summarising the history and 

 geographical distribution of the main type, a detailed description of the inflorescence 

 and flower is followed by notes on the variations ordinarily met with, and students 

 find food for thought and for further observations of their own on other plants in 

 the incidental note that " being a highly specialised floral mechanism, the flower 

 of the violet is remarkably constant under cultivation. Improved garden forms 

 and florists' varieties differ only in the larger size of the plant parts as a whole and 

 of the petals of the flower, the essential organs remaining practically unaffected." 

 The floral diagram and sectional elevation planned on a comparable scale serve to 

 elucidate the primary construction of the adult flower and are supplemented by a 

 detailed study of its developmental history, the illustrative figures being those obtain- 

 able by the use of a " low power." The development of the special mechanism of 

 the flower is similarly traced, and incidentally interesting notes such as the use of 

 " syrup of violet " paper as a test for acids and alkalies previous to the introduction 

 of litmus are given. Pollination, with notes on the habits of various insect visitors 

 and their comparative dexterity, a good account of cleistogamy, monstrosities, and 

 the fruit and seed complete this very full survey of the type. The allied forms 

 Viola tricolor var. arvensis (the corn pansy) and Viola altaica (the garden pansy) 

 are next fully dealt with, and the section concludes with a discussion of theoretical 

 considerations which arise out of a study of the genus Viola in relation to other 

 types and to other members of the same natural order. This general discussion 

 will be of great interest and value to students apt, quite naturally, too often to 

 regard natural orders as sharply delimitated divisions, by the author pointing out 

 that the very existence of the order Violacece is probably due to the wide distribu- 



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