142 THE NATURE AND VARIETIES OF 



mation of mosses whilst yet in the confervoid state. The 

 fact, however, is denied hy Professor Milne Edwards, who 

 considers that the cluster is formed by subsequent gemma- 

 tion from the first individual ; and the matter remains open 

 for further investigation."* 



10. A few remarks may be made, in conclusion, in re- 

 gard to the cases of " alternation" which occur- in the Ve- 

 getable Kingdom. Here marked phenomena of this kind 

 are confined to the Cryptogamia. In the lower section of 

 this division including Algae, Fungi, and Lichens in- 

 stances probably occur of all the forms of alternation above 

 referred to, as will appear from the summary of the repro- 

 ductive process in these orders, given in Chapter II. But 

 as no one form occupies a preponderating place, and as 

 most of the phenomena of reproduction are still so imper- 

 fectly known in these plants, it would be premature to at- 

 tempt any generalizations as to the character of the process 

 as a whole. 



The higher Cryptogamic species fall very naturally into 

 two groups, corresponding to the Muscales and Filicales 

 of Lindley, and distinguished by differences alike in struc- 

 ture, habit, and development. The structure of the repro- 

 ductive organs themselves (antheridia and archegonia) is 

 very similar in these groups, the diversity, as already no- 

 ticed, lying in their direct connection in the former with the 

 leafy axis, while in the latter they are contained in detached 

 gemmse or phytoids. It was remarked, at the same time, 

 that from these relations of the reproductive organs, some 

 botanists would argue a correspondence on the one hand 

 between the structures from which they spring, that is, be- 

 tween the leafy axis of the fern and the stalked capsule of 

 the moss ; and on the other, between the bodies into which 

 the spores germinate, i.e., the prothallium and the leafy 



* Compar. Physiol., 4tli Ed,, p. 571. 



