106 MUSCALS. [BOOK i. 



evidence of the identity of nature of these bodies, and that 

 the pulverulent ones are at least not anthers, as has been 

 supposed ; for in Isoetes the pulverulent inner bodies have 

 the same organisation, even to the presence of what has been 

 called their stigma, as the outer granular ones; so that, if 

 Isoetes has sexes, it will offer the singular fact of its anther 

 having a stigma. The anatomy of Isoetes is described by 

 Mohlinthe Linnaea, xiv. 181." (Vegetable Kingdom, p. 73). 



3. THE MUSCAL ALLIANCE.* 



(Urnmosses, Splitmosses, Horsetails, Scalemosses, Liverworts, 

 and Crystalworts.) 



In the structure of URNMOSSES (Bryacese or Musci) and 

 SPLITMOSSES (Andrseacese), neither vessels nor wo*ody tissue 

 are employed. Their stem consists of elongated cellular 

 tissue, from which arise leaves also composed entirely of 

 cellular tissue without woody tissue ; the nerves, as they are 

 called, or, more properly speaking, ribs, which are found in 

 many species, being formed by the approximation of longer 

 cells than those which constitute the principal part of the 

 leaf. The leaves are usually a simple lamina ; but in Poly- 

 trichum and a few others they are furnished with little plates 

 called lamellae, running parallel with the leaf, and originating 

 in the upper surface. 



At the summit of some of the branches of many species 

 are seated certain organs, which are called male flowers, but 

 the true nature of which is not understood. They are 

 possibly organs of reproduction of a particular kind, for both 

 Mees and Haller are recorded to have seen them produce 

 young plants. Agardh says they have only the form of 

 male organs ; and that they really appear to be gemmules. 

 By Hedwig they were called spermatocystidia ; by others 

 staminidia or ahtheridia. They are cylindrical, articulated, 

 clavate, membranous bodies, opening by an irregular perfora- 

 tion at the apex, and discharging a mucous granular fluid. 

 Among them are found slender, pellucid, jointed threads, 



* Vegetable Kingdom, p. 54. 



