421 
4rium and many other Liliaceae, and Carex (whose tussocks, aris- 
ing from a common stock, consist of relatively antidromic plants). 
This fact may have a bearing on the problem of homology of 
seeds and root-buds, and may suggest a diversity between sub- 
terranean and ordinary cauline buds. 
During the past summer I have enlarged my range of ob- 
servations on this subject by help of the great botanical gar- 
dens and museums of Europe, and have found light on some 
difficult points.* Among the numerous additional evidences 
of antidromy I may cite many Cactaceae (as Mammiillana), 
Tamarix Gallica, Screw Pines (Pandanus utilis, etc.). and gener- 
ally the palms. Dr. Urban, of the Berlin Botanische Museum, 
has published papers on the spirally twisted fruits of species of 
Medicago, and of certain genera of Loasaceae. His monograph of 
the genus Medicago shows that most of the species have a sinis- 
trorse twist, a few (as MW. tuberculata) mostly dextrorse; and he 
knows of no clear case of one individual plant having two kinds 
of twists among its fruits. These results on the whole harmonize 
with the general rule of antidromy; and they seem to be well es- 
tablished by his large collection of specimens which he kindly 
Showed me. [I also examined living specimens of this genus in 
the Botanische Garten, but failed to correlate the spirality of the 
fruits with the phyllotaxy of the plant which bare them: this 
failure was due to the difficulty of deciding the order of phyllotaxy 
of such straggling plants. His paper on Loasaceae brings out the 
interesting facts that in some of the species the fruits are spirally 
twisted, the direction of the twisting being either one for a, species 
(several Species of Cajophora), or constant in a genus (Blwmen- 
bachia) and dextrorse or locally specialized, all the plants from one 
locality being alike, but different for the same species between 
different localities ( Sclerothrix); or the fruits following one an- 
other in one specimen may be antidromic (species of Cayophora). 
*T beg to express my thanks for courtesies extended by the officers of Kew Gar- 
dens, England ; of the Jardin des Plantes, Paris; by Mr. F. A. Bather, of the Natural 
History Museum, London; Herr Otto Miiller, of the Botanische Garten of the Uni- 
Versity of Strassburg; and Dr. Ign. Urban, of the Museum der Koenigl, Botan. Go: 
‘en of Berlin. I may explain that in quoting Dr. Urban I render his word “ dextrorse 
by “sinistrorse ” and conversely, so as to turn his terminology into conformity with 
Our method of designating the spiral thread of a common screw as « dextrorse.” 
