ORGANS OF REPRODUCTION. 557 



bracteoles of the Paronychiacea}, or if not, at least partially (as in 

 many white flowers), or are so far dead that their cells are entirely 

 filled by special matters or substances not calculated to sustain 

 chemical processes (as most of the coloured bracts and petals). It 

 is only the calycine and carpellary leaves that exhibit an active 

 vegetation not different from that of the stem-leaves. 



The function of protecting the tender, newly-developed parts by 

 a firm enclosure around the buds against the influences of the 

 atmosphere, and against excessive moisture which readily produces 

 decomposition, belongs to all leaves, without any exception. They 

 continue to protect these tender parts until the development of the 

 epidermal system enables them to resist these injuries. This last- 

 named function seems to be that which is more especially performed 

 by calyx and corolla. As soon as the flower has opened itself, the 

 sepals and petals may be removed without injuring the development 

 of the seed and fruit in the slightest degree, provided they do not 

 still serve the purpose of protecting the tender organs of repro- 

 duction against rain, &c. ; or if, after their removal, the transfer of 

 the pollen to the stigma is rendered impossible, an artificial transfer 

 is substituted. 



The leaves also become organs of attachment in the form of 

 cirrhi. 



B, Organs of Reproduction. 

 a. Cryptogamia. 



222. Among the Angiospora, the sporangia are the only parts 

 to which we can attribute a definite function, namely, that of 

 forming the spores, of which they are the parent-cells. We know 

 nothing of the object of the other parts of the sporocarp, and, indeed, 

 it is very improbable that they should possess any other than a 

 morphological significance. The nature of the so-called anthers has 

 been already explained ( 84.). 



There are likewise parent-cells of the spores in the Cryptogamia 

 and Gymnosporce, which, as such, exercise an important function. 

 The sporocarps only serve as envelopes of the spores, and facilitate 

 and regulate the distribution of the spores by their hygroscopic 

 properties. With regard to the Antheridia, we can state for certain, 

 that not a single fact exists from which we could infer, in the 

 remotest degree, that they have the slightest connexion with the 

 function of reproduction. Every thing that has been hitherto 

 written on this subject are only fine-spun fancies, founded upon 

 decidedly false analogies. 



It may be further stated, that we are still ignorant with regard 

 to the peculiar function possessed by the external spore-case in 

 relation to the development of the spore. It is possible that it may 

 be principally intended, through its indestructibility, for the pro- 

 tection of the delicate cell of the spore against injurious agencies 



