227 



On Azolla and Salvinia. By W. Griffith, Esq. F. L. S. 



Memb. Imp. Acad. Natur. Curios., Royal Ratisb. Botan. 



Soc, Asst. Surgeon, Madras Establishment. 



Having lately had an opportunity, one of the many which 

 theH. C. Botanic Gardens afford, of examining Azolla and 

 Salvinia, I now purpose giving my observations in detail. 

 For I believe that there is no part of structural, and con- 

 sequently systematic Botany, more enveloped in obscurity 

 and mystification than these two genera, the examination 

 of which appears to have been limited to their mature state. 



It is necessary in the first place to observe that in Azolla 

 and Salvinia the so-called, or supposed male and female or- 

 gans are up to a certain and comparatively late period of 

 their development indistinguishable, a circumstance of pri- 

 mary importance, of which I have been long aware.* 



The first stage of the two organs (ovula) observed in 

 Azolla has presented them enclosed in an involucrum of a 

 very cucullate form, the point turned inwards so as to touch 

 the axis. They are sessile cellular bodies of a concave or 

 cup-shaped form, the cup (the young tegument) being occu- 

 pied by a protruding cellular body (the nucleus) ; one is rather 

 more advanced than the other. (PL 15. /. 1.) 



The second stage presented them of a more oblong form, 

 the protruding cellular body more surrounded by the cup, 

 (PL 15./. 2. 3.) by which in the third it is completely enclosed. 

 (PL 15./. 4.) 



* The first opportunity I had of seeing Azolla was in 1837, during a journey 

 across the Jheels of Eastern Bengal. I then became aware of the identity of the 

 male and female organs up to so late a period as precluded their being intended 

 to perform such opposite functions : of the other observations then made it is only 

 necessary to notice the delineation of the granules within the organs in that stage 

 when they often appear to form a column reaching from the foramen to the nucleus, 

 The similarity of the two organs was mentioned to Mr. Solly, and by him brought to 

 the notice of the Linnean Society. 



