1904] BRIEFER ARTICLES 295 
Tate, a highly specialized inflorescence is no place to look for simple 
‘Structures. 
_ According to their stages of development, three sets of anemophi- 
lous plants may be recognized: (1) those closely related to entomophi- 
lous ones and evidently of recent origin; (2) plants whose development 
from Entomophilae is not so evident, but which have dehiscent poly- 
Spermous fruits, one-seeded dehiscent fruits, or one-seeded indehiscent 
_ 8roups, which are themselves entomophilous, but contain anemophi- 
lous species: Thalictrum, Fraxinus, Sanguisorba (Poterium), Acer ; 
Salix, also, if Warming i is right in regarding the Greenland species of 
Salix as anemophilous.* Less recent are Ambrosia in Helianthoideae, 
Ricinus in Euphorbiaceae, Rumex in Polygonaceae, Platanus in 
- Rosales, Amarantaceae in Centrospermales, Plantaginaceae in Sympe- 
_ talae, Juncaceae in Liliales. On the other hand, none of the anemo- 
_ philous groups have produced forms which could reasonably be regarded 
as recently developed entomophilous ones. 
/ In the recent cases the fruit does not differ essentially from that of 
_ the entomophilous forms from which they were derived. 
The Plantaginaceae compose the only anemophilous family of 
‘Sy mpetalae and show every indication of being recent. The stigma is 
single, but is, no doubt, modified from a completely compound one. 
_ The number of seeds varies greatly, but some of the flowers are subject 
_to spontaneous self-pollination and others may be more or less etomo- 
philous. . 
Populus has two to four stigmas, a syncarpous fruit with two to four 
valves, two to four parietal placentae, and numerous coma-bearing 
seeds. From these characters I would suppose that Populus was not 
only of entomophilous origin, but recent. It has seemed to me remark- 
able that Miiller should have regarded Populus as a primitive anemophi- 
‘Ous form and Salix as a recent entomophilous form derived from the 
htomophilous polyspermous forms having similar fruit and seeds. So, 
*Om nogle grénlandske blomster. Sv. V. Ak. Ofy. 1886: 116, 131, 158. 
