422 UTEICULAEIA NEGLECTA. Ciiap. XVII. 



surfaces. The glands are variously affected by absorp- 

 tion ; they often become of a brown colour ; sometimes 

 they contain very fine granules, or moderately sized 

 grains, or irregularly aggregated little masses ; some- 

 times the nuclei appear to have increased in size ; the 

 primordial utricles are generally more or less shrunk 

 and sometimes ruptured. Exactly the same changes 

 may be observed in the glands of plants growing 

 and flourishing in foul water. The sj)herical glands 

 are generally affected rather differently from the 

 oblong and two-armed ones. The former do not so 

 commonly become brown, and are acted on more 

 slowly. We may therefore infer that they differ some- 

 what in their natural functions. 



It is remarkable how unequally the glands on the 

 bladders on the same branch, and even the glands 

 of the same kind on the same bladder, are affected by 

 the foul water in which the plants have grown, and by 

 the solutions which were employed. In the former 

 case I presume that this is due either to little currents 

 bringing matter to some glands and not to others, or 

 to unknow^n differences in their constitution. When 

 the glands on the same bladder are differently affected 

 by a solution, we may suspect that some of them 

 had previously absorbed a small amount of matter 

 from the water. However this may be, we have 

 seen that the glands on the same leaf of Drosera are 

 sometimes very unequally affected, more especially 

 when exposed to certain vapours. 



If glands which have already become brown, with 

 their primordial utricles shrunk, are irrigated with 

 one of the effective solutions, they are not acted on, 

 or only slightly and slowly. If, however, a gland 

 contains merely a few coarse granules, this does not 

 prevent a solution from acting. I have never seen 



