66 Anatomie. — Varietäten etc. 



appears to be unilacunar in the seedling as in the adult. In Paeo- 

 nia the first foliage leaf contribntes, in some species, live Strands 

 to tlie vascular cylinder, while the later ones have the usual trila- 

 cunar insertion. 



As regards the stem cylinder, the main departure from the 

 type is the siphonostelic appearance described by Jeffrey in 

 Ranunculus and Anemone, and here shown to occur also in Caltha 

 and TroUius. Evidence is brought forward in favour of its wholly 

 secondary origin. Agnes Arber (Cambridge). 



Curtis, K,' M., The Anatomy ofthe six epiphytic species 

 of New Zealand Orchidaceae. (Ann. Bot. XXXI. p. 133—149. 6 

 pl. 1917.) 



The orchids dealt with in this memoir are: Eavina nntcronata, 

 E. suaveoleus, Dendrobium Cunjiinghainiij Bulbophyllnm pygmaeurn, 

 B. tuberculaturn and Sarcochilus adversus. 



The results may be summarized as follows: Root. The velamen 

 consists of one row of ceils in Bulbophyllmn pygmaeurn and B. 

 tuberculatum and of two or three rows in Sarcochilus adversus; the 

 number in the two species of Earina and in Dendrobium Cunning- 

 hamii is more variable, ranging from three to five, or more. The 

 greatest amount of Chlorophyll, in proportion to the size ofthe root, 

 occurs in Sarcochilus adversus, and next in the two species of 

 Bulbophyllum . Less is present in the Earinas and in Dendrobium 

 Cunninghamii. A great number of speciall}^ thickened waterstorage 

 cells are present in the cortex of the root of Sarcochilus adversus; 

 they are also to be seen, though less frequently, in the two species 

 of E Irina. Fungal hyphae are present in the roots of all. 



Stem. An internal cylinder of sclerenchyma occurs in the stem 

 and branch of Earina mttcronata; there is no complete sheath of 

 sclerenchyma in E. suaveoleus. A peripheral cylinder of scleren- 

 chyma occurs in Dendrobiu}n Cunninghamii. 



Leaf. Isolated sclerenchyma Strands are present in the leaves 

 of the two species of Earina; a 'palisade' arrangement of thin- 

 walled cells containing little Chlorophyll occurs beneath the upper 

 epidermis of E. suaveoleus. Very large vascular sheaths but no 

 isolated Strands are present in Dendrobium Cunninghamii; its wide 

 epidermis is muscilaginous. The leaves of the species of Bulbo- 

 phyllum are succulent; mucilaginization takes place in the walls; 

 pseudo-bulbs are present. The leaf of Sarcochilus adversus is very 

 succulent; great numbers of raphide cells occur throughout. 



Agnes Arber (Cambridge). 



Bond, T. C, On the primary and secondarj'- sex-charac- 

 ters of some abnormal Begonia flowers and on the evo- 

 lution of the monoecious condition in plants. (Journ. of 

 Genetics. IV. p. 341—352. 1915.) 



In BegoniaSj abnormalities from the monoecious type of sexual 

 arrangement are almost alwaj^s associated with abnormalities of 

 accessory and of essential floral parts: i.e. instability in primary 

 sex elements carries with it instability of equiübrium of somatic 

 tissues. 



The association of sexual instability (as indicated by the herma- 

 phrodite condition of the flower) and modification of accessory 

 floral parts is also shown in the genetical behaviour of Begonias. 



