HAP. VI] 



ANIMALS 



145 



Like the ant-fungi and tlic acacias referred to, Cccropia affords an 

 xceptional case of the voluntary surrender by the plant of protcid 

 ibstances even in relati\cl\' 

 irge quantity, for Miillers 

 Drpuscles are produced con- 

 nuously and in profusion. If 

 e cut througli the brown 

 elvcty coating (Fig. (Si), we 



c among the hairs numerous 

 ensely crowded objects of the 

 ind represented in the various 

 ages of development. Having 

 rown to their full size, these 

 odies become loose at the base 

 id are pushed to the surface by 

 le pressure of the clastic hairs 

 lat are crowded together side 

 y' side. Their developmental 



story, as well as the presence 



a stoma at the apex of each, 



lows that Miiller's corpuscles. 



vc those of Belt, are to be 



arded as metamorphosed 



ands ; they do not however 

 Ifil the functions of glands 



en in their early stages. 



hilst normal leaf-glands, with this exception, 



cur only on young leaves and forthwith die, 



e glands of Cccropia converted into nutritive 



dies for ants are continually produced during 



e whole life of the leaf, and are continually 



cd when they are gorged with albuminoids. 



The assumption that the entrance-door and 



i-iller's corpuscles represent adaptations to 



ts was surprisingly confirmed by the dis- 



very in the Corcovado, near Rio de Janeiro, 



a species of Cccropia devoid not only of tlic 



is but also of the entrance-door and of Miiller's 



■piisclcs (Fig. 82). In this case also the young 



illary bud presses on the internode and thus 



-ises the formation of an isodiametric de- 



tssion, which subsequently, owing to the 



Fig. So. Cecropia atlenopus. Base of the petiole 

 with pulvinus and Miiller's corpuscles. Natural size. 



igitudinal growth, gives place to a groove. 



Fig. Si. Cecropia adenopus. 

 Transverse section of part of the 

 velvety coating at the base of 

 the petiole, with Miiller's cor- 

 puscles in various stages of de- 

 velopment. t>lightly magnified. 



But the original depression 



