8 I'KOLIKERATION IN CONTROL OF BOLL WEEVIL. 



tissue colls upon the boll weevil. It is consoquontly of an entomolog- 

 ical and not a botanical character. The botanical significance of the 

 phenomenon has been very fully considered by Mr. O. F. Cook, of the 

 Bin"eau of Plant Industry, to whose publications among those listed 

 below'* the reader is referred for a discussion of that ])art of the subject. 



DEFINITIONS. 



In order that the statements here made may be readily understood 

 by one who is not familiar with terms used in botany or entomology 

 a few general definitions may be in order. In Bulletin No. 45 of the 

 Bureau of Entomology, concerning the cotton boll weevil, the term 

 "gelatinization" was used instead of proliferation, as it was believed 

 that its significance would be better understood by the average reader, 

 though it was realized that, strictly speaking, the term used expressed 

 an incorrect idea concerning the nature of the change to which it 

 referred. The term "proliferation" is in general use both in botany 

 and zoology, to denote a growth by the multiplication of elementary 

 parts. In the present case we may define proliferation as being the 

 development of numerous elementary cells from parts of the bud or boll 

 which are themselves normally the idtimate product of combinations 

 of much more highly specialized cells. The resulting product is thus 

 composed of comparatively large, thin-walled cells, which are placed so 

 loosely together that the resulting formation is of a soft texture, and 

 has a granular appearance (PI I, fig. 1) which may be plainly seen 

 with the unaided eye. The soft, pulpy nature of this growth led to the 

 choice of the term" gelatinization" as being most appropriate to signify 

 in a general way its appearance and texture. It appears that this forma- 

 tion may originate from various causes in almost any part of the bud or 

 boll (PI. I, figs. 2-4). Whatever may have been tiie inciting cause, the 

 character of the formation appears very much the same in any case. 

 Undoubtedly, however, certain tissues proliferate more readily than 

 do others. In squares, the outer layer of the column upon which the 

 stamens are borne appears to be especially susceptible to stimuli which 

 produce this reaction. In bolls, the cells immediately adjoining the 

 thin, hard layer lining the hulls or carpels are most frequently the 



a Bibliography of Proliferation: 



1904. Iluiitpr, W. D., and Hinds, W. E.— The Mexican Cotton Boll Weevil. Bui. No. 

 45, Bureau of Entomology, U. S. Dept. Agric., pp. 96-97. 



1904. Cook, O. F. — Evolution of Weevil Resistance in Cotton. Science, Vol. XX, pp. 

 666-670. 



1905. Hunter, W. D., and Hinds, W. E.— Bui. No. 51, Bureau of Entomology, U. S. 

 Dept. Agric, pp. 133-134. 



1905. Cook, O. F. — Cotton Culture in Guatemala. Yearbook U. S. Dept. Agric, f. 

 1904, pp. 47.5-488. 



1906. Cook, O. F.— Weevil Resisting Adaptations of the Cotton Plant. Bui. No. 88, 

 Bureau of Plant Industry, U. S. Dept. Agric. 



