CONTRIBUTIONS TO SOUTH-AFRICAN BOTANY. 467 
The pseudopodia were never seen to return to the mode of 
development of an ordinary vegetative axis with normal leaves. 
This mode of asexual reproduction in Aulacomnion palustre 
is of interest when compared with that well known in Aulacomnion 
androgynum and Tetraphis pellucida. In these plants the struc- 
ture of the gemma is simpler, consisting of but few cells, and it 
presents few points in common with the normal leaf. The speciali- 
zation to perform the function of asexual reproduction is in fact 
more advanced in these cases, while the transition from the leaves 
to the gemme isa sudden one. In Aulacomnion palustre the spe- 
cialization is less complete: the transition from the normal leaf to 
the leaf-gemma is in this plant gradual, and the modification of 
growth of the axis, which bears the gemme, is comparatively 
slight. 
Contributions to South-African Botany. 
By Harry Bots, F.L.S.* 
[Read January 17, 1884.] 
ORCHIDE®. 
Disa, HERSCHELIA, MONADENIA, and BROWNLEEA. 
In the Society’s Journal, vol. xix. pp. 235-236, I suggested the 
maintenance of the genus Herschelia, and relied, in part, for its 
distinction from Disa upon its bilobed stigma. Mr. Bentham 
also took the same view in the ‘Genera Plantarum.’ I have 
since found this character to be inconstant, several species ex- 
hibiting in some individuals a more or less well-marked third 
lobe. There are then left the characters of the trifurcate ros- 
tellum, and the single gland of the pollinia. With respect to the 
* [Specimens of the Orchids described in the following paper were sent to 
Kew by Mr. Bolus, with the request that they might be compared with those in 
the Kew Herbarium, and also, if possible, with Thunberg’s types of his ‘ Flora 
Capensis.’ Through the courtesy of Professor Berggren, of Upsala, I have 
been enabled to examine Thunberg’s types ; and the result has been to show 
that some of the species deemed by Mr. Bolus to be new, are in reality species 
that were long ago described by Swartz and Thunberg. As, however, many 
of these old species have been misunderstood by Lindley and others, it has been 
thought advisable to publish the descriptions and commentaries given by Mr, 
Bolus, merely substituting the correct names for those he had proposed, and 
adding synonyms, additional localities, collectors’ names, &c. Of Thunberg’s 
Cape Orchids I propose to give an account hereafter. —N. E. Brown, Herbarium, 
Kew.] 
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