INTEODUCTION TO CllYPTOGAMlC BOTANY. 425 



467. As in former instances, and indeed in every artificial 

 arrangement, there are exceptions to these characters. In 

 Cyathodimn there is something like the peristome of mosses ; 

 in some Jungermanniw, the rupture is irregular; in Andrwa, 

 which appears to me a moss, the fissure is valvate, with the 

 tips cohering as in Jungermannim ; in several mosses there 

 is no peristome, and in soine the lid does not separate ; and in 

 Dancea and its allies there is no ring. In all these cases, 

 however, the afiinities are so clear, that the student will ex- 

 perience little difficulty when the exceptional cases are once 

 pointed out. 



468, Characece are analogous to Gonfervce, Hepaticm to 

 Lichens, while some Marsileacece have almost the foliage of 

 Phrenogams. There is, however, no more connection between 

 the two former groups and their analogous Thallogens, than 

 there is between the latter and Phagnogams. Thallogens and 

 Acrogens belong to two definite divisions, as acutely separated 

 from each other as PhjEnogams are from Cryptogams. There 

 is not, as far as I am aware, a single real link like that be- 

 tween Alga3 and the animal kingdom. Their affinities are far 

 too strongly stated in Dr. Lindley's Vegetable Kingdom, p. 52. 

 Riccia has no relation that I can see to Lichens. The other 

 instances mentioned of the relation of Clubmosses to Conifers, 

 Ferns to Yews, and Mosses to Dacrydium, are all mere cases 

 of analogy. 



ALLIANCE III 



Characeales, Berk. 



Acrogens consisting of confervoid articulated threads, simple 

 as in Gladophora, or compound as in Polysiphonia. Fruit 

 monoecious or dioecious. Female : spores coated with spirally 

 arranged cells, at once reproducing the plant. Male : brick- 

 red globules, consisting of eight spherically triangular divisions, 



