164 ON THE NARDOO PLANT OF AUSTRALIA. 
smoothness of the fruit (for the other characters alluded to by Dr. 
Hanstein are of less importance), Dr. Hanstein’s sporocarps might have 
belonged to a different species. Through the kindness of Sir William 
and Dr. Hooker, I have lately had the opportunity of examining a 
number of species of Marsilea in the Kew Herbarium, and I feel satis- 
fied that the covering of the fruit cannot be trusted as distinctive of 
species. This series of specimens shows that M. macropus, Hook., 
varies considerably in size and in the covering of the sporocarps. I 
find amongst them a small plant in which parts of the same individual 
fruit are densely covered with hairs, and other parts are quite bald and 
minutely punctate; and although no sporocarp upon this specimen is 
so entirely bald as to accord with Dr. Hanstein’s specific description, it 
is clear to my mind that the nature of the surface of the fruit depends 
upon its age and the friction to which it has been exposed, and that it is 
quite possible for sporocarps originally hairy to become absolutely naked. 
Kew specimens have also cleared up some doubts which I had en- 
tertained, and which arose from the relative size of M. macropus, Hook., 
and the plants raised by Dr. Moore. In the * Icones Plantarum’ M. 
macropus is deseribed as a span long, whereas the fronds of the plant 
raised by Dr. Moore are upwards of a foot in height. . The difference 
in size would have led me to doubt the identity of. the Nardoo. with 
M. macropus ; but this doubt was removed by finding in the collection 
at Kew a plant undoubtedly of the same species, with a frond at least 
fifteen inches long. The apex of the full-grown leaflets in Dr. Moore’s 
plant certainly cannot be described as erose ; they are almost entire, but 
sometimes very slightly crenate with the indentations far apart. This 
latter character however could not for a moment be relied upon as of 
specific value. 
_ The result of what has been stated would seem to be that the plants 
raised by Dr. Moore are identical with M. macropus, Hook., although, 
until the former have fruited, which they have not yet done, the point 
cannot be considered settled. I am also inclined to believe that Dr. 
Hanstein’s sporocarps were the produce of the same plant, and that his 
proposed new species cannot be retained, | 
Dr. Hanstein made some interesting remarks upon the germination 
of the fruits in question. These remarks, although not altogether new, 
are, I think, more complete and better illustrated than those of any 
previous writer upon the same subject, and occurring as they do in a 
