DOGBANE AND MILKWEED. 687 



twenty-five blossoms I have counted five flies thus held in cap- 

 tivity — three dead and two dying — and the same bunch had 

 captured a long-legged, lace-winged caperer, whose struggles to 

 free himself were as desperate as futile. On any large bunch of 

 these flowers one can see mementoes of past tribulations. Here 

 and there a blossom still holds a little black leg, the price of the 

 liberty of some insect who has gone off free, but a cripple. 



A flower so highly organized as the milkweed seldom receives 

 and nourishes all comers. In one peculiarity of structure the 

 milkweeds are like the orchids, that royal family of plants, for 

 the orchids also send their pollen abroad massed into two clusters, 

 which are united by a disk. But each orchid has its own very 

 select and small circle of guests, and some among them endeavor 

 to please one butterfly or moth friend, him and him alone. They 

 are, in evolutionary language, " highly specialized." 



On the other hand, a flower which keeps open house to all 

 comers is generally primitive in color and structure. Such blos- 

 soms are apt to be yellow or white, with flat, open corollas, and 

 without spurs, honey jars, or covering to protect the pollen. So 

 the milkweed is something of a problem to the evolutionary 

 botanist. Can he, for example, explain the fate of those hapless 

 flies which, like Haman of old, come to a feast, but get only im- 

 prisonment and death ? These unfortunates are but a small pro- 

 portion of the milkweed's fly visitors. The great majority make 

 off, after taking their fill of nectar, without carrying off any por- 

 tion of the pollen which the flower is endeavoring to send to its 

 neighbors. This waste of nectar is bad for the milkweed, which 

 would be better off with fewer fly visitors. So the flower would 

 profit by any device which would discourage these many flies, 

 without deterring those useful and desired visitors, the bees. 

 Will flies learn after a while to shun the milkweed's dangerous 

 sweets, so that they may all be left for worthier and more wel- 

 come guests ? And how many generations will it take this pro- 

 verbially foolish insect to lay the lesson to heart ? 



A SUBSIDY of one hundred thousand francs has been voted by the Bel- 

 gian Chambers for the expedition to be led by M. Lieutenant de Gerlache, 

 co-operating with the Belgian Geographical Society, into the antarctic 

 regions. Two seasons are to be spent in the expedition. In the first season, 

 M. de Gerlache will attempt the exploration of the regions around Graham's 

 Land. Then, after wintering in an Australian port, the Belgica, as the 

 vessel is to be named, will sail for Victoria Land, and an effort will be made 

 to determine the southern magnetic pole. While he will reach as high a 

 latitude as he can, M. de Gerlache's chief aim will be to collect data rela- 

 tive to meteorology, terrestrial physics, oceanography, and the fauna and 

 flora of the regions explored. 



