374 



ORGANOGRAPHT. 



Saloinia differs from Marsilea and Pilularia, in producinj^ 

 several arclicgonia, instead of only one, as is the case with 

 them. Azolla requires further investigation. 



In reviewing the fructification of the Marsileacese, we find 

 that, it differs i^i-om the Fihces and Equisetaceae, in producing 

 two distinct kinds of spores, and in the pro-thallus not forming 

 a distinct expansion on the outside of the spore as is the case 

 with them, but being confluent with the spore. These cha- 

 racters show that, the Marsileacea3 are nearly allied to the 

 Lycopodiacete, ^^hich we now proceed to describe. 



4. LYCOPODiACE.aE OR Club-mosses. — The fructification in 

 this family is situated on the upper surface of the leaves at their 

 bases {Jigs. 795 and 796). The leaves thus bearing the fructi- 

 fication are frequently collected together into a kind of cone or 

 spike (Jic/. 156), while at other times, they are scattered along 

 the stem. The spores, like those of Marsileacese, are of two 

 kinds, and are enclosed in separate cases. These cases are 

 variously named ; the names which Avoula correspond to those 

 just used in describing the Marsileaceae would be sporangia and 

 antheridia ; but the former are also commonly called oosporangia 

 or oophoridia {fig. 795), and the latter pollen-sporangia {fig. 

 796). The contents of the former are generally termed large 

 spores or macrospores {fig. 798), those of the latter small spores 



Fig. 795. Fig. 796. 



Fig. 797. 





!<7. 798. 



Fifi. TO.*!. Scale or leaf of " SelaginfUa apoda " with oosporanffium or oophoridium 



in it* axil. After Tlcnfrev Fig. 7!W>. PoVcn-gporanqium or anlheridium of 



the above. After llenfrey. Fi(j. 707. Pollen-cporansinni of a spocien of Sela- 



gineVn. It i« two-viilxcd, and contuins a iminbcr of smuil spores or viicrosporcs. 



/-Vf/. 798. OoBporniiKiiiin of a Hpt-cics of ScliKjinilUu Tliitf is a two-vulved, 



four-lobcd aac, and contains four large spores or ovules, called macrospores. 



or fnicrosporex (fig. 797). It is greatly to be regretted that a 

 uniform nomenclature should not be adopted with the repro- 



