LINNEAN SOCIETY OF LONDON, - 96 
directly opposite the five alar fissures, a slight means of communi- 
of the five anthers, five radial furrows are in consequence left, by 
means of which the papillar tissue of the stigma, which he finds 
clothes the whole inferior surface of the stigma- ‘disk, is exposed. 
rom a very complete study of the different stages in the deve elop- 
ment of the pollen-mass in Aselepias, : appears that this genus 
presents, in its entire details, a perfectly unique, isolated, an 
peculiar case of formation. The setae stages are only to be found 
paralleled in the single instance of Zostera (which had been studied 
by W. Hofmeister), a genus that affords either the most primitive 
or the most aberrant type of pollen formation known. The later 
kingdom. The late period iy which the tapetum persists, and the 
conversion of those walls its cells whieh adjoin the contents 
of the loculus into cutin ‘ form the firm investing membrane 
of the pollen-mass, the absence of an endothecium, and the e peculiar 
mode of Heaton of the anthers, are among the especially note- 
worthy features. In connection with fertilization, the mode of 
ormation i 
other is elucidated, and these series are shown to be of two kinds, 
viz., unilateral and dichotomous. Cross-fertilization is the great 
law in Aselepias, and in some eases it is requisite that the cross 
should be not onl between distinct flowers, but between those 
of distinct individuals produced from seed in order that progeny 
may result, the plant apparently being self-impotent to its own 
pollen. Mr. Baker then read the second part of his ‘ Contributions 
to the Flora of Madagascar,’ in which he dealt with the deserip- 
tions of about one hundred and sixty new gamopetalous dicoty- 
ledons, gathered in Madagascar by recent English is cea 
especi ially ¢ the Rey. R. Baron, F.L.8.. of the London Missio 
ociety. The most interesting is Schismatoclada, a new genus 
of Rubiacee allied to Cinchona. The other new genera are Tetra- 
spidium, of the group of semiparasitic sila arena such as 
Pedicularis and Melampyrum, which turn completely black in 
ing, remarkable for its four shield-shaped one- “celled anthers ; 
Franciscan monk. Of representatives of well-known European 
genera the present collection includes two species of Anagallis 
nearly allied to tenella, two Ajugas, a Salvia, two Micromerias, three 
species of Stachys, five Senecios, three Cynoglossums; and a Lysi- 
machia. The genera represented mn most largely are Da nais, ee 
Helichrysum, Gabi Clerodendron and Hypoestes, There i a single 
species of the beautiful Avaitiasious genus Strobilanthes, ‘which i is 
