120 MYSTERIES OF THE FLOWERS 



ward, permitting the insects to go their way. 

 Though the vines grow luxuriantly about my 

 home, bearing numerous flowers,'! have failed to 

 find any of them bearing seed-pods, from which I 

 conclude that the Aristolochia is absolutely depend- 

 ent upon insects, and that 

 its favourite guests in 

 the insect world are not 

 to be found in these 

 parts, though we have 

 plenty of other and less 

 useful sorts. Possibly, 

 however, the cause may 

 be that too few vines 

 grow in this vicinity 

 to furnish the requisite 

 crossing of pollen with 

 distant flowers, as was 

 noted in the case of the 

 sterility of the trumpet- 

 creepers growing here- 

 about. 



Milkweed — Asclepias syriaca 

 July- August 



The most complicated 

 MILKWEED mechanism among our 



