1881.] NATURAL SCIENCES OF PHILADELPHIA. 451 



northeastern Pennsylvania and contiguous parts of New Jersey 

 he had seen it the past season, in a number of places in gardens, 

 and in most cases it was stated that the plants had originally been 

 obtained from almost inaccessible places on the high hills of that 

 part of the country. The fact that in these remote places trees 

 from the distant nurseries are seldom obtained, together with the 

 fact that the plant is not now nor probably has been for many 

 years cultivated in American nurseries, makes it possible that the 

 reports are true, and the plant may be found in the spurs of the" 

 higher Allegheny range. The highly viscose character of this 

 species is interesting. The excretory glands are low and broad, 

 with a crater-like mouth, from which the sticky matter flows, and 

 soon covers the stem as with a thick coat of varnish. The viscid 

 strength was such that in some instances the mere contact with a 

 lead-pencil was sufficient to draw a branch towards the person 

 pulling it. So man}^ plants with viscid secretions have insects 

 found adhering to the sticky matter, that it has been shrewdly 

 suspected the secretion in such cases is a design for entrapping 

 insects, from which the plant perhaps obtains a better supply of 

 nitrogen than in the ordinary manner through the atmosphere. 

 In the case of this clamm}^ locust no insect was found adhering, 

 though it would seem probable that some few, b}' blind accident, 

 at least, ought to have been found there. For what purpose in 

 the economy of the plant this secretion is formed, cannot be 

 conjectured. From this view of individual benefit alone to the 

 plant, or to the race, the secretion seemed an enormous waste of 

 nutritive power. This waste seemed even more conspicuous in 

 the inflorescence. It was too early to judge of the amount of 

 seed the plants would produce ; but many flowers had fallen, 

 leaving no ovarium behind in a single instance. There were no 

 indications that a solitary seed-vessel would result from all the 

 flowers which had expanded np to that time ; and if any seed 

 perfected, they would have to be from a few of the later flowers. 

 In any event, the amount of waste material in the barren flowers 

 was enormous. 



Here it was remembered that a belief widely prevails which 

 regards flowers and insects as having been interadapted to each 

 other. It is believed not only that flowers are often to be cross- 

 fertilized by insects before they can perfect seed, but that special 

 insects are adapted to certain plants, which in the absence of 

 these special insects remained barren. An ally of this clammy 

 Robinia, Robinia hispida, has been under culture in America and 

 Europe for a great many years ; but the speaker said he had 

 never seen nor knew of any one who had seen a single seed-vessel 

 from any garden plant. He had come to believe it probable that 

 some special insect, adapted to the pollinization of this plant, 

 existed in the native place of growth of this species, but which 

 insect had not followed the plant in its artificial distribution over 

 the earth. This season he had found the plant, for the first time 



