E. Regel on Parthenogenesis. 313 
have observed but superficially, and that neither Spinacia nor 
Mereurialis are to be included among plants which can furnish 
proof of parthenogenesis.” 
Plants of Spinacia, Mercurialis annua, and Cannabis were 
planted singly in pots; and the male plants were removed 
‘ay comprehension. ; 
ay plants of Mercurialis were cut in and observed in the 
Ye described manner. Lach of the few tufts of blossom pro- 
male fs great number of female flowers. Here, again, solitary 
locas Owers continually made their appearance, so that I have 
_ ay removed more than twenty of them from each of the 
| year aren plants. Even with the most careful observation, 
this lutely conclusive result could scarcely be obtained with 
> Plant; for the male flowers are only detected after they have 
phe and therefore may have scattered pollen. I used m 
and in Srtenrors to i Pag the male flowers at the right time; 
fait, al “a hitherto neither of the experimental plants have set 
But i. earliest developed female flowers having withered up. 
tp ese plants should still set fruit, this must be attributed 
, .-4 Teceived from some of the male flowers. 
fluence - -—Difficult as it is in Mercurialis to neutralize the in- 
is still oe pollen from adventitiously developed male flowers, it 
Raven. cult with Spinacia. All the experimental plants 
flow, os I observed at first, in the axillary tufts of female 
Over the itary normally developed anthers, which pene 
* the female flowers. I removed them, and placed the plants 
ae Tha 
th sina’ Bot {et full observations upon Cannabis; but this will doubtless fur- 
cc - ae Vou. XXVI, No. 81.-MAY, 1859. ° 
