ON THE FROND-CELLS OF LEMNA AND WOLFFIA. 375 
In April, I completed an enumeration of the Indian species of 
Acanthacee, which has been sent to London for publication. The 
Curator of the Herbarium has contributed to the ‘ Journal of Botany ’ 
and the Linnean Society’s Proceedings, papers on the Synonymy of 
Didymoplezis pallens, Griff., a very rare and obscure Orchid found in 
lower Bengal; on the Asiatic species of Lemnacez, and Notes on the 
Indian Bambuse. 
(At the meeting of the Linnean Society, on November 1st, the paper 
on Indian Acanthacee, referred to by Dr. Anderson, was read. It was 
entitled an ** Enumeration of the Species of Acanthacez of India, Cey- 
lon, Burmah, and the Malayan Peninsula." The author having revised 
the African and most of the Asiatic genera, though hesitating to de- 
cide on the limits and affinities of the genera until the American species 
have also been examined, nevertheless is of opinion that the limits of 
the Asiatic genera, and of the larger groups, such as suborders and 
tribes, will not be materially altered when the entire Order comes to be 
revised. The views he has adopted concerning the limits and relations 
of genera, and the grouping them into tribes and suborders, are essen- 
tially different from those of Nees von Esenbeck, whose division of the 
group into two suborders, by the nature of the placental processes of 
` the seeds, he regards as exceedingly unequal. In the arrangement he 
himself proposes, the suborder Z/unbergidec is separated from Ruel- 
lidee and Acanthidee by the nature of the calyx, the estivation of the 
corolla, and the peculiar processes which support the seeds ; while the 
Ruellidee and Acanthidee, almost co-extensive with Nees's great group 
of Echmalacanihee, are readily distinguished from each other by the 
szestivation of the corolla, which is strongly contorted in the first and 
imbricated in the second. In Hwellidee the tribes are established on 
characters taken principally from the calyx and form of the seed; in 
Acanthidee they are easily distinguished by the form of the corolla, 
the number of stamens, and the condition of the anthers. The long 
paper consisted chiefly of a technical account of the species.—Ep.] 
ON THE FROND-CELLS OF LEMNA AND WOLFFIA. 
Bv Georce GULLIVER, F.R.S. 
My researches,—epitomized in the * Popular Science Review,’ Oct. 
