180 Miscellanies. 



ularly in vegetable anatomy and physiology, that this portion of the 

 work has necessarily been entirely re-written, and has assumed almost 

 a new aspect in the present edition ; and even during the short period 

 that has elapsed since its publication, many interesting discoveries 

 have been made. The additions most worthy of notice are a new and 

 more minute classification of elementary tissue, recently proposed by 

 Morren ; much interesting matter concerning the generation of cel- 

 lular tissue ; a good account of recent discoveries respecting the va- 

 rious forms of tissue composed of membrane and fibre combined, 

 which are found to be of almost universal occurrence ; the article on 

 the laticiferous tissue of Dr. Schultz; and that on Raphides, con- 

 cerning which there is an account in the appendix by Mr. Queckett. 

 In the chapter on the compound organs of flowering plants, there is 

 an account of the views of Prof. Mohl concerning the structure of 

 endogenous stems; an analysis of Bronn's memoir on the spiral dis- 

 position of leaves ; and much additional information concerning the 

 structure and development of pollen, which will be new to most Eng- 

 lish readers. The remarks on placentation are interesting, especially 

 as the subject is now exciting considerable attention ; Dr. Lindley 

 defends, for the most part, the doctrines of Schleiden and Endlicher 

 on this subject. The chapter on the chemical constitution of the 

 elementary organs, is condensed from the researches of Payen and 

 Schleiden, which are models of chemico-physiological investigation. 

 The most interesting additions to the subject of vegetable fertiliza- 

 tion, are the analysis of Mr. Griffith's recent memoir on the singular 

 structure and the impregnation of the ovulum of Santalum ; and a 

 (too brief) notice of the novel doctrines which have lately been 

 broached by Endlicher, Schleiden, and others respecting the sexuality 

 of plants. The opinion of Endlicher is " that what we call pollen is 

 analogous to the spores of cryptogamic plants, and that consequently 

 the anther is a female organ, whose contents perform an act similar, 

 to that ^f germination when they fall upon the stigma." The view 

 of Schleiden, although differently expressed, amounts to the same 

 thing ; he also considering the anther as nothing but a female ovarium, 

 and each grain of pollen the germ of a new individual. The subject 

 is exciting much attention ; and since the publication of this edition 

 of Dr. Lindley's work, Mirbel has read a paper before the Institute 

 of France, in which the views of Schleiden are attacked, and the com- 

 monly received Linnasan hypothesis defended. It is to be regretted 

 that there is no detailed account of this controversy in the English 

 language. The idea which seems to have given rise to these specula- 

 tions is undoubtedly true, viz. that the organization of pollen and of the 

 spores of cryptogamic plants is remarkably similar, and that their 



