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not yet determined, as they are in fragmentary condition, 
and also an Eleocharis, sp. incert. 
Of Graminese about 10 to 12 specimens, including Era- 
grastis ciliaris (Link.) ; Panicum, 2 species ; the abundant 
Dactyloctenium iEgyptiacum (Willd.) and Eleusine Indica 
(Ggertn.) and Cenchrus tribuloi'des (L.). The curious creep- 
ing Monanthochloe littoralis (Englemann) also occurred on 
the southern sandy shores. 
Only one Fern, that being Aspidium patens (Sw.), but 
Mr. Fday noted Acrostichum aureum (L.) and Anemia 
adiantifolia (L.) as well. 
A Chara occurred plentifully in a pond toward the 
south portion of the island. 
Dr. Alcock read some notes on Frog Tadpoles, illustrated 
by drawings. He said the life of the tadpole may be divided 
into periods, each characterised by the developments which 
take place in it. He described the first and second periods, 
leaving the remainder to be treated of in a future paper. 
The first period extends from the deposition of the ovum 
to the escape of the young tadpole from the egg membrane. 
In our climate this occupies about a fortnight, the first week 
being spent in the segmentation of the yolk, the second in 
the development of the embryo. In a mass of frog spawn, 
however, the ova on the surface hatch first, and are followed 
by the others in succession to the centre of the mass, so 
that there is a difference of about a week between the 
earliest and the latest. The structures which have been 
developed when the embryo escapes from the egg are the 
cerebro-spinal axis and its supporting skeleton, with the 
continuation of these structures in the tail, the enclosing 
body- wall, rudimentary organs of sense, the visceral arches, 
the oral aperture and the cavity of the mouth, the heart, 
and the blood vessels of the developing parts ; but the cavity 
of the abdomen remains filled with undifferentiated yolk- 
