GENERAL REMARKS. 



265 



the yellow sac in its lower half, and in its upper, the conden- 

 sed points. 



The trilineal mark of the apex of yellow sac is evidently its 

 relation with the superimposed mass, for in the young state it 

 appears here puckered up, as if it were trifacial. 



Appearances indicate a similarity between the condensed 

 points and abortive sporules, but the difficulty is, that this is 

 uniform, affecting the central points of the lobes equally, 

 which it should not do. 



The hair like processes of incrustation of yellow sac, are not 

 organic. 



These anomalies I do not pretend to explain, the phe- 

 nomena nevertheless are worthy of the attention of ob- 

 servers, and are in my opinion entitled to the explanation 

 I have endeavoured to give them. I therefore beg to propose 

 to Botanists, Salvinidae and Charidse as the naked seeded 

 types of Acotyledones. 



SALVINIA. 



5. The incrustation has, I think nothing in common with 

 the original grume : it first appears as an incrustation of very 

 minute granular matter : it continues so, until it has acquired 

 considerable thickness. Then cavities appear to be formed in 

 it, and it hence it assumes a cellular aspect ; but I have not ob. 

 served these seeming cells to be provided with a proper 

 membrane. The incrustation adheres firmly at an early period. 



The contents of the smaller pedicellced bodies are solid, 

 white, opaque. I have not observed them to be distinctly 

 cellular, in which respect the organisation is less advanced than 

 in Azolla, even under 1-16 they appear like condensed grume, 

 with indications of cellular looking sub division on the edges. 

 Pressure shews them to contain trifacial cells, of a yellowish 

 colour, together with larger globules, which I do not think are 

 cells, but analogous to the globules in the incrustation. The 



m 2 



