NOTES AND MEMORANDA. 401 



lutely hyaline lobose pseudopodia. The outline of the nucleus 

 is not strongly marked, but the nucleolus is obvious enough. 

 In others you may find one or two, three or four, or a crowd 

 of twenty green-coloured granules. These granules have a 

 uniform size, and a peculiar form, being concavo-convex discs 

 or cups. 



Spongilla, as is well known, is frequently colourless, or 

 rather of a pale salmon colour. Hence it might be suggested 

 that the green granules (the chlorophyll-bearers) are para- 

 sitic, as it has been suggested that the starch-bearing yellow 

 cells of Radiolaria are parasitic. However, in the colourless 

 Spongilla sponge-cells are found which contain colourless 

 granules, corresponding to the green-coloured granules of 

 the green sponge-particles. These colourless granules are, 

 however, less definitely disc-like in form than the green ones, 

 and are often irregular and angular. 



It has been found that in the orchid Neottia, where 

 chlorophyll is absent, a green colour may be developed by 

 the action of strong sulphuric acid. 



I have found that precisely the same thing is true of the 

 colourless specimens of Spongilla Jluviatilis. When im- 

 mersed in strong sulphuric acid they gradually develop a 

 strong leaf-green colour, fully as intense as that of the 

 naturally green specimens. Microscopic examination after 

 or during this treatment is not very satisfactory, but the 

 colourless granules appear to be the parts which first turn 

 green, though after the reagent has acted the whole mass of 

 coagulated sponge-sarcode is uniformly impregnated with a 

 green colour. 



I remember to have seen it stated somewhere, on chemical 

 evidence, that Spongilla contains a starch-like body. I 

 should be glad if any reader of the Journal can refer me to 

 an authority for this statement. 



The above observations tend to show that chlorophyll in 

 Spo7igilla, as in the higher plants, is preceded by a distinct 

 chlorophyll-evolving substance, which is colourless. — E. Ray 

 Lankestbr, September ^Oth. 



Scalariform Ducts in the Prothalli of Ferns. — I have lately 

 detected scalariform vessels in the prothalli of ferns which 

 are quite similar to those described by Dr. Farlow in Pteris 

 creiica. I am uncertain, however, of the species to which 

 the prothalli belong, as I pick them out of a fern case in 

 which I grow a variety of species of difierent genera. The 

 scalariform vessels make their appearance just below the 

 notch and run out towards it. In some there is a linear 

 thread of one or two strands, in others a cluster of vessels— 



