Johnson — Callosities of Nitophyllum versicolor. 159 



of a Liverwort. The cellular filaments of the callosity serve to 

 give anchorage to the germinating callosity. The callosity forms 

 the stalk of the new plant, the emptiness of the cells of the stalk 

 being due to the consumption of the food matter in sprouting. So 

 far as I know no such condition of things is known in any other 

 Floridean. 



5. Accepting this view of the nature of the callosities Nito- 

 phyllum versicolor, Harv., is, in all probability, simply a gemmiferous 

 state of N. Bonnemaisoni, Grrev. 



6. The mode of formation of the callosity does not agree with 

 Schmitz's views as to the structure of the Floridean thallus. This, 

 as far as it goes, favours the retention of the Bangiacese in the 

 FloridesB. 



EXPLANATION OF PLATE XIV. 



Fig. 1. — (After Greville's figure 3 in Sc. Crypt. Flora PI. cccxxii.) 

 Natural size. c. callosity with cellular filaments. 



Fig. 2. — Callosity in surface view. t. thallus. Slighfcly magnified. 



Fig. 3. — Cross-section of callosity. Slightly magnified. 



Fig. 4. — Same, x 80. 



t. thallus ; c. callosity ; c.f. a cellular filament. 



Fig. 5. — A cell of callosity showing reserve products, x 240. 

 Fig. 6. — Cross-section of stalk, outline. Slightly magnified. 



