84 THE PLANT WORLD. 



from this swollen part. Since they are so closely packed together, 

 the branches naturally are very slender and straight, and receive a 

 portion of their name, at least, from their resemblance to a broom 

 made of twigs. 



Early in the summer of 1895, while walking in Anne Arundel 

 County, Maryland, the peculiar appearance of two bushes by the road- 

 side was pointed out to me by my companion. In a little hollow by 

 the roadside, growing in sandy soil among the common weeds were 

 two bushes with curious tufts of slender branchlets, and long slender 

 pinnate leaves of unmistakably leguminous appearance, though en- 

 tirely unfamiliar. The general aspect of the branches, with their 

 characteristic prickly spines at the nodes, led at once to the suspicion 

 that these were nothing but abnormal specimens of Robinia P'seiidaca- 

 cia. This was shown conclusively to be the case by the appearance of 

 normal leaves last year. The leaves had the usual number of leaflets, 

 but the latter were only about one-half their usual length and were 

 not more than a fourth of an inch in width. These slender leaflets on 

 the tufts of thin branches gave the bushes a very striking appearance. 



Specimens were carried home and were shown to the late Dr. J. 

 E. Humphrey, then lecturer in Johns Hopkins University, who at once 

 said they looked like "witches' brooms." He made a thorough study 

 of this material and of more brought in later, and to his surprise found 

 not the slightest trace of fungus hyphse or fructification in or on the 

 tissues. Under the microscope, thin sections showed that the wood 

 was very much gnarled and twisted, and a section through a node re- 

 sembled somewhat a piece of bird's-eye maple. We must, therefore, 

 ascribe the formation of so many adventitious buds and such abnormal 

 foliage to something else than fungus enemies. Both bushes were 

 formed of strong shoots from stumps cut off near the ground, but it 

 .does not seem likely that this cutting back could cause the great 

 changes, especially as the shoots were apparently a year old. The 

 following summer one bush was dead and the other had only a few 

 abnormal leaves on it, but none of the usual size and shape. Last 

 spring there were no abnormal leaves, and just a few that looked like 

 those usually seen. Evidently the bush was in a very sickly condition 

 and it is doubtful whether it will be alive in 1898. 



The January number of the Botanical Gazette contains a portrait 

 and biographical sketch of Dr. Julius von Sachs, the distinguished 

 German botanist, who died May 29, 1897. He was one of the pioneers 

 in the study of plant physiology and many a difficult problem owes its 

 solution to him. 



