239 



arrangement and development can be determined very satisfactorily. 



In the vegetative portion of the hypha, the nuclei are of considerable 

 size and lie in the inner part of the wall-lining of protoplasm. They are 

 united by peculiar plasma threads, that run parallel or obliquely to the 

 long axis of the hypha. The nuclei are ellipsoidal, elongated in the dir- 

 ection of the long axis of the hypha. One can determine the existence of 

 a small nuclear body in each nucleus. In the hypha-ends the nuclei are 

 nearer together. Here they are found somewhat closely connected in 

 pairs, and lying entirely imbedded in the wall-lining of protoplasm. 

 After the formation of the partition wall, they increase in numbers, by 

 division, in the sporangial portion, and in the mature sporangium each 

 zoospore contains a nucleus. 



CoNTRIJiUTIONS TO THE LIFE-HISTORY OF NOTOTHYLAS. By D. M. MoTTIEK. 



[Abstract.] 



This paper embodies the results of a study of the development of the 

 sporogonium and sex-organs of Notothylas orbicularis together with that 

 of Anthoceros. These results may be summed up as follows : 



The capsules of Notothylas orbicnlans possess a columella varying in 

 size with that of the capsule. 



The columella is developed, as in Anthoceros, primarily in the young 

 sporogonium with the archesporium and independent of it, and is not a 

 secondary differentiation inside the spore chamber. 



The archegonium of Notothylas resembles more closely that of the en- 

 sporangiate ferns than does the archegonium of Anthoceros. 



The antheridium arises from an hypodermal cell, thus differing in this 

 respect from all other known Bryophytes. 



The ash of tree.?. By Mason B. Thomas. 

 The object for which this investigation was undertaken was to show by 

 chemical analysis the amount of food a tree or shrub takes from the soil 

 in its yearly growth. The method employed was to determine by a quan- 

 titative analysis of the ashes of trees and shrubs, the proportion of the 

 mineral constituents of the soil that are found present in them. It seems 



