DEPARTMENT OE BOTANICAI. RESEARCH. 63 



with the tube containing the pollen nucleus and attendant structures. These 

 and other facts therefore lead to an amended conclusion that external agents 

 affecting heredity exert this action most readily by influencing the pollen 

 derivatives and not the egg-cells. 



Successive generations of the earlier derivatives, notably that of Oenothera 

 biennis, have been made with the result that the newly assumed characters 

 have been found fully transmissible and stable in the recently originated line 

 of descent. 



Physiology of Storage Organs. — Seeds, bulbs, tubers, and corms of a num- 

 ber of species, which show adaptations for the storage of water, have been 

 accumulated for cultivation, and various experimental tests are under way by 

 which this capacity of the plant may be understood morphologically and as 

 to possible modifications transmissible from one generation to another. 



Fasciations. — An investigation of the morphology and heritability of 

 fasciations was begun by Miss A. A. Knox in the New York Botanical 

 Garden in 1906 and completed in 1907. The principal results are ready for 

 publication. 



Great differences are found among the deformations of stems known as 

 fasciations, and this diversity is found to depend upon the localization of the 

 injuries to which the deformation is due. The injuries in question were 

 found to be due to the action of the ovipositor of a moth, Mompha, in laying 

 eggs, or to the ravages of the larvae hatched from them. 



Stems injured in the center of the apex or irritated there may produce 

 ring fasciations by a spreading of the apical meristem in radial distribution. 

 Those injured on the side may become linear fasciations, and a larger, wider 

 attack of irregular kind produces the protuberances. The time of the attack 

 makes a great difference in the development. If the injury is to the growing 

 region of a biennial plant still in the rosette stage, the plant fasciates during 

 the rosette period, and the growing region becomes linear before the time 

 of the elongation. The stems are then flat from the base. If the plant is 

 adult at the time of the invasion, the injuries are in the upper part of stems 

 which have already completed their first growth. These fasciated stems 

 are round below and flat above. In a given field of plants it will also be 

 noticed that most of the fasciated individuals begin to flatten from the same 

 relative point on the axis. This seems to indicate that the banding is stimu- 

 lated in all of them at the time of the advent of the new swarm. In an 

 adjoining field, apparently of similar character, the failure of a swarm, or 

 its less penetrating mode of attack, may account for the absence of any degree 

 of fasciation whatever. These modifications were not found to be trans- 

 missible in any degree, and hence differ very essentially from fasciations due 

 to internal causes — causes which are themselves transmissible from genera- 

 tion to generation. 



