THE AMERICAN BOTANIST. 115 



(Mertensia) the columbines rhodotlendrons and various 

 otheiheathworts. Nearl\- a hundred diiferent species have 

 been thus punctured. ' The bumble-l)ees( Bo/77 /?ns) and the 

 carpenter-ljees {Xylocopa) are responsible for much of the 

 mischief, though wasps are said to occasionally aid in the 

 work and various other insects visit the punctures for 

 hone3' but do not make new ones. The insects making 

 these perforations, are those with short tongues that find 

 it ditiicult to get the nectar in the regular \va\'; but since 

 perforated flowers are likely not to be pollinated, the wily 

 insects seem to be killing the goose that lays their golden 



Flowers of Clematis. — Most botanists know in a 

 general way that the flowers of the common virgin's 

 bower {Clematis virginiana) are dioecious, that is, that 

 stamens and pistils are borne on separate plants, but it is 

 doubtful if many of them could describe the flowers cor- 

 rectly. The plant which produces the pollen has flowers 

 possessing only a calj^x and stamens, but the pistillate 

 plant has, in addition to the calyx and pistils, two or 

 more whorls of abortive stamens. These stamens are still 

 equipped with rudimentary anther-sacs but the pollen is 

 absent. The stamens are not entirely useless, however, 

 for, as the calyx w^ithers, the filaments broaden, become 

 white and spread out in the plane occupied by the sepals 

 making a sort of corolla. The flowers are visited by mul- 

 titudes of tiny black flies less than an eighth of an inch 

 long and these are probably the chief agents in pollination, 

 though the blossoms also attract various other insects, 

 especially certain flies about the size of house-flies and a 

 handsome black and white moth of medium size. 



The Local Distribution of Plants.— At the extreme 

 southwest corner of Wellington County, Ontario, lies 

 Puslinch Lake, a body of water about a mile and a half 

 long by a mile wide. In the middle of the lake is an 

 island about 350 yards in diameter, with scattered 

 clumps of bushes and trees, and with a patch of swamp 

 on the north side. On this island there are four plants 



