190 



parts have lost it by formation of nematliecia or from other causes. The meeting 

 point between tlie overhipping frond witli another similar one or with the forth- 

 growing old frond is usually easily found (fig. 112 B *). The places from which 

 the new fronds are given off are frequently inverted conical, being upwardly en- 

 larged and composed of filaments slightly divei-ging upwards. The number of these 



Fig. 112. 



Cruoriellu codana. A, marginal part ol' frond seen from below. 195:1. B and C, vertical sections of frond showing 

 the overlapping of the frond by a new lobe; at » the point of concretion of this lobe witli another part of the frond ; 

 in C llie basal layer of the new lobe is not normally developed. In C auxiliary-cell filaments and sporogenous fila- 

 ments are visible 205:1. D, vertical section of frond with anthcridial nemutliecium 350:1. 



points of departure is variable; sometimes they are very close, in other places they 

 are more distant. The new-formed fronds coalesce laterally and form together a 

 uniform plain surface. The cells of the basal layer of the overlapping fronds were 

 frequently found connected with pits, a fact which supports the here proposed ex- 

 phmation of their development. As the new fronds were evidently not produced 

 at the season when the specimens were collected, I have not been able to follow 

 their development, but must content myself with examining the advanced stages. 

 A further fact confirming my view is that nematliecia are frequently found on the 

 surface of the covered crust (fig. 112 C). The under face of the frond is often 



