146 BOTANICAL GAZETTE. [ June, 
mature fruit, referred to this species, differ somewhat in 
_ foliage from typical L. scopulorum, and simulate Coniose- 
_ linum Canadense so very closely that mature fruit is neces- 
k before any decision can be made. 
aa Wabash College, Crawfordsville, Ind. 
— 
. 
Sa Zygomorphy and its causes. 
CHARLES ROBERTSON. 
2 Since reading a foot-note in Gray’s Structural Botany’ re- 
ee ferring to the observation of Sprengel, that irregular flowers 
_ of an irregular flower which is wind-fertilized,”’ I have ofte?. 
wondered what are the conditions in the insect relations © 
48 are in the direction of irregularity. In the observation of 
, the behavior 
* d. ' 
% Two papers on the causes of zygomorphy have Sie» 
appeared, one by Herman Véchting® and the other by Broei< 
erick Delpino.* My observations approach the subject from 
4 stand-point so different that it is hardly necessary to iV 
_ More than references to these papers. However, it may, 
wel, y Way of introduction, to mention some of the pons 
i d I 
= ies egularity Delpino recognizes 
if s % * ; 08 
i ©80NEs, viz., the instrumental ind mechanical (cause st 
52" 109 note t 
Jes ® Ueber Zygx ib Acer Pred tobe he: uk. Ba. XV 
«HLT, 1986. 997-8 om orPhie und deren Ursachen. Jahrb. fiir wissench. Botanik. 
Be Wiggers’, See also Bot, Zeit. 1887 490 
sue cause, Malpighia, Anno I, Fasc. VI, 1886, 245-262. 
