On the Pithophorace^e. 



21 



rise to a cauloid easily recognized as such by its being ramified and, 

 in fertile specimens, by its carrying spores. A rhizoid is, in this case, 

 not developed, but it often happens, that the lowest cell of the caulo'id 

 forms, in its lower end, within the membrane of the germinated spore, 

 a new basal spore (pi. 4, fig. 12 sgb)\ see the preceding paragraph 1. c. 

 Specimens of this kind I have found only of P. Cleveana nob., but not 

 so very few. The first transversal cell-wall is in this case, as in the 

 preceding one, placed above the germinated spore in the cauloid (pi. 4, 

 fig. 12 iv). It is easily understood by the account of the formation of 

 spores contained in the preceding paragraph, that this wall must be 

 formed before the two situated below marked w' and w". In one spe- 

 cimen of P. Cleveana nob., the one represented pi. 4, fig. 15, I have 

 found a transversal cell-wall in the germinated spore, seemingly without 

 the spore's having been elongated downwards in germinating. The little 

 cell, ?7«, situated below this parting wall must thus per analogiam be 

 regarded as the rhizoid of the plant, (In this specimen also a basal 

 spore is found in the cauloid). 



The nature of certain specimens of P. heivensis nob. and of P. 

 Roettleri (Roth) nob. gives reason to suppose, that other deviations 

 from the normal proceeding of the germination may possibly take place. 

 The specimen represented pi. 4, tig. 7 shows, proceeding immediately 

 out of the germinated spore, a side branch, ac, pointing somewhat down- 

 wards. It is possible, that this branch may have been formed already 

 in the germination, and in this case the spore would have sent forth no 

 less than three processes, one upwards, one downwards and one side- 

 ways; but it might also be possible, — and this seems to me more prob- 

 able, — that this branch has been formed later, when the lowest cell 

 of the cauloid had already attained its completion ; in the same manner 

 as we sometimes find, in P. Cleveana nob., that the lowest cell of the 

 cauloid has, after the germination, formed a spore in its lower end. 

 The branch marked ac on pi. 4, fig. 10 might be analogous to the side 

 branch mentioned above (pi. 4, fig. 7 ac), though it points upwards in- 

 stead of downwards. *) The probability of the opinion, that the branches 

 now mentioned are not formed in the germination, but later, is supported 

 by the nature of the specimen which is represented pi. 4, fig. 9. There 

 we see an almost full-grown specimen just in the act of developing, from 

 its lowest caulo'id cell, a basal branch, ac, pointing downwards. 



') Possibly this might be the case also with the branch marked ac belonging 

 to the specimen of P. ZeUeri (v. Mart.) nob. represented pi. 1, iig. 12. 



