INTRODUCTION TO CRYPTOGAMIC BOTANY. 77 



imbibe nutritious matter from the soil or matrix, but this is 

 very far from being a universal attribute. When fronds 

 are present, they are seldom disposed symmetrically, except 

 they take the form of threads ; in which case they exhibit, at 

 times, the most exquisite arrangement, so as to make them 

 objects of much admiration, and some of the most symmetrical 

 occur amongst species of inferior dignity. The symmetrical 

 arrangement of the subulate processes in Chara, does not come 

 under the present head ; for the nature and mode of origination 

 of the spermatozoids associates these plants evidently in the 

 second great class of Acrogens. 



60. A third common character is afforded by the nature of 

 the fruit. In a few simple cases the process of fructification 

 consists merely in the division of the mother cell ; but, in 

 general, the reproductive bodies are due to the thickened end 

 of certain of the component threads, which ultimately separates 

 and forms sometimes a single spore, consisting of a double cell 

 wall with its endochrome, or of a multitude of endochromes 

 produced by division of the cell ; in other cases, however, the 

 endochrome of the cell itself (which is then called an ascus), 

 becomes organised without any change of the inner membrane, 

 and presents a definite or indefinite number of distinct repro- 

 ductive bodies. In many instances, both the spore-bearing 

 threads and asci are naked; but very often, they are either 

 permanently contained as a lining in distinct organisms, or at 

 length exposed to the open air ; sometimes, they form a tuft, 

 springing from the base of the fructifying cavity, after the 

 fashion of a central placenta. 



61. Another distinctive feature consists in their various modes 

 of fructification, in the same individual species. This has long 

 been notorious in the case of the more important Algae, and it 

 is daily becoming more evident amongst Fungi, and will, pro- 

 bably, be extended to the whole group. It is difficult at pre- 

 sent, in the absence of direct observations, to say precisely what 

 is fruit and what is not, as it appears that in many cases the 

 secondary form may be representative of male organs, if not 

 functionally such. Certain it is, at least from the observations of 

 Thuret, that the spermatozoids of Fuci, which our countryman, 



