418 Trcmsactions. — Botany. 



the development of the flowers, or, which is more probable, 

 the pollen must be shed early into the pendulous flowers, and, 

 bein^ caught in the sac made by the closed petals, is thus 

 brou'^^ht into contact with the stigmas. In all the flowers 

 examined by me the ovaries stood always too high to receive 

 pollen directly on their stigmas, unless it reached them m the 



manner suggested. . -, ■■ ^i t 



No definite cause has been assigned for the occurrence of 

 cleistogamic flowers in plants. The Eev. George Henslow, m 

 "The Origin of Floral Structures" (p. 262), gives several 

 examples of species which produce normal flowers m one dis- 

 trict or country and cleistogamic flowers m another, showing 

 that the change appears to be due to variations m climate or 

 soil &c • but no law can be adduced from the examples given. 

 That the occurrence of this phenomenon depends largely on the 

 supply of moisture is suggested by the following fact : Some 

 plants of violet (cultivated forms of Viola odorata) growing in 

 mv garden, in a border against a wall— a position m which they 

 were subjected to great heat and where they got very httle 

 moisture— were found covered with cleistogamic flowers, and 

 bore very numerous seed-capsules, although they produced no 

 conspicuous flowers. Other violets of the same variety, grow- 

 in- only a few feet away, but in a border where they were 

 exposed to the weather and got abundance of moisture, had 

 abundance of normal but no cleistogamic flowers. 



I can -ive no explanation of the specimens of Melicope 

 from Lake Van aka, as I have no record of the soil or climatic 

 conditions of Pigeon Island ; but the profusion of flowers, not 

 one of which was open, and of maturing fruit, arrested my 

 attention at once, and I noticed that all the plants seen by 

 me were so covered with these peculiar self-fertihsed closed 

 flowers. 



Aet. XIAl.—Bemarlcs on the Genus Abrotanella, Cassini, 

 ivith Descriptions of Neio Species. 



By T. Kirk, F.L.S. 



\Eead before the Wellington Philosophical Society, 24th February, 

 ^ 1892.] 



Plate XXXVI. 



Abrotanella was founded by Cassini in 1825 on a plant from 

 the Falkland Islands, which for some years was considered to 

 be the only species. In 1845 Sir Joseph Hooker constituted 



