28 CIRCULAR NO. Ill, BUREAU OF PLANT INDUSTRY. 



tip of one of the carpels were that a threadlike projection extended 

 beyond the normal carpels. Fertilization may have taken place 

 through this extended tissue. It remains to be seen whether these 

 seeds are capable of producing plants, but their presence in such a 

 mature form proves most emphatically the real nature of these 

 abnormalities. Mr. Clark's own description of the specimen found 

 at Clarksville follows: 



A boll of an Upland variety of cotton found at Clarksville, Tex., in the fall of 1912 

 had developed between the placenta? two large supernumerary carpels which con- 

 tained two apparently normal seeds. One of these abnormal carpels was thick and 

 hard, resembling a normal carpel except that it was narrower (8 millimeters) and 

 attached along its back to the placenta of a normal carpel for half the length of the 

 normal boll. From here it projected independently. Although this projection had 

 be'en broken off before the specimen was found, it must have extended to the apex 

 of the boll and have furnished means of fertilization for the seeds. The other carpel 

 had the appearance of a thin obovate leaf, measuring 1 centimeter in width and about 

 2 centimeters in length. This was attached only at the base. Three veins could be 

 easily traced in this leaf-like carpel and the surface was dotted with oil glands, but it 

 is doubtful whether placentge had been developed on the margins. Two locks were 

 contained within the cavity formed by these two abnormal growths. One lock con- 

 sisted of two apparently normal seeds and three rudimentary ovules. The other con- 

 sisted of rudimentary ovules only. The two seeds, though a little undersized, pro- 

 duced abundant lint, that of one measuring 33 millimeters and of the other, 25 milli- 

 meters in length. The surrounding boll wa" in other respects normal, with the excep- 

 tion that the five placentae of the carpels were flat and widened to about 3 millimeters. 



OCCURRENCE ON OTHER PLANTS. 



At Washington, D. C, on the grounds of the Department of Agri- 

 culture, are several plants of althaea (Hibiscus syriacus) which in 1911 

 were abnormal in this same respect. Supernumerary carpels, two to 

 five in number, develop between the placentae, although the normal 

 series of carpels are not distorted. The central carpels in some cases 

 contain rudimentary ovules. 



[Cir. Ill] 



