26 CIRCULAR NO. Ill, BUREAU OF PLANT INDUSTRY. 



At Lanham the abnormality occurred particularly in the bolls of 

 a new type of Upland cotton introduced from the State of Durango, 

 Mexico, but it was also found in the Triumph, a Texas variety. Since 

 1908 the same abnormality has been observed in other varieties at 

 different points in the United States and has been given more thorough 

 examination. 



OCCURRENCE AT GLENDALE, CAL. 



During the seasons of 1910 and 1911 more perfect examples of this 

 abnormality were found at Glendale, Cal., both in green and open 

 bolls. Here the resemblance to miniature carpels was very plain. 

 None of the Upland varieties grown at Glendale were exempt from 

 this abnormality, while only one or two cases were found in several 

 rows of different varieties of Egyptian cotton. Although the vege- 

 tative parts of the plants showed no excessive growth, the bolls com- 

 monly grew to an unusual size. These were frequently abnormal. 

 A large number of bolls had the carpels separated at the apex and in 

 some cases the carpels were distinct to the base, with the exception 

 of the parts along the placenta?. 



At Glendale supernumerary carpels sometimes developed in other- 

 wise normal bolls, but they were most frequently associated with 

 the bolls having separated carpels. The true carpels of such bolls 

 were loosely connected, and the inner faces of the placentae were 

 flattened or hollowed to provide space for the central carpels. Al- 

 though they completely filled the space between the placenta?, the 

 abnormal carpels were in no way attached to the true carpels or to 

 the placenta?. Supernumerary carpels measuring more than an 

 inch in length by three-eighths of an inch in breadth were frequently 

 noted. Ovules, an eighth of an inch or less in length, producing 

 extremely weak fiber, which in some cases measured half an inch, 

 developed within the compartments of the supernumerary carpels, 

 apparently without fertilization. In open bolls the supernumerary 

 carpels became dry and woody and the compartments split along 

 the back. Through the narrow slits the fiber emerged, and the 

 resemblance to a miniature boll was striking. 



RELATION OF CLIMATIC CONDITIONS TO ABNORMALITY. 



There appear to be similarities in the climatic conditions of the 

 localities where these supernumerary carpels have been observed 

 to develop most frequently. At Lanham, Md., and Glendale, Cal., 

 the climatic conditions are not favorable for the production of 

 cotton on a commercial scale. At Lanham the growing season is 

 generally too short to mature a crop before frost, and the bolls 

 seldom ripen normally. At Glendale the nights are cool for most of 

 [Cir. in j 



