66 



important than the thickness of tlie layei-s of vegetable matter is the 

 character of the tissues through wliich the i^uncture passes. Thougli 

 corolla and calyx are both modifications of original leaf tissue, both 

 have changed so greatly in form and texture that the resemblance is 

 recognized only by those somewhat acquainted with j^lant structure. 

 The corolla, moreover, has changed far more than has the calyx, and 

 in becoming so highly specialized its tissue has lost certain powers 

 still retained by the green calyx tissue. The particular power referred 

 to in this connection is the ability to heal small wounds. Punctures 

 made in the corolla must, therefore, remain open, while small punc- 

 tures through the calyx will in most cases be healed by the natural 

 outgrowth of the tissue, so as to completely fill the wounds in a man- 

 ner entirely analogous to the healing of wounds in the bark of a tree. 

 The custom of the weevil of sealing up its egg punctures with a mix- 

 ture of a mucous substance and excrement is of great advantage and 

 assistance to the plant in the healing process. While undoubtedly 

 applied primarily as a protection to the egg, it serves to keep the 

 punctured tissues from drying and decay, and thus promotes the 

 process of repair. 



As a result of the growth thus stimulated in the calyx, the wound 

 is perfectly healed in a short time, and, as is the case in the healing 

 of the bark of trees, here also we find a corky outgrowth projecting 

 above the general surface plane. This prominence the writer has 

 termed a ' ' wart " (PI. X, fig. 40) . The healing is comi^leted even before 

 the hatching of the egg takes place, and thus both egg and larva par- 

 take of the benefit of its protection. 



It is possible for the i)uncture to heal without the full development 

 of the wart, and it is also possible for eggs to develop successfully 

 even when the puncture was made through the corolla alone and no 

 wart developed, but in the latter case the chances are rather against 

 it. Occasionally warts do develop from feeding punctures which 

 were small, but the exact conditions under which this takes place 

 have not been determined. 



THE ACT OF OVIPOSITION. 



The general process of making punctures has been described pre- 

 viously under the topic of "Food habits" (p. 38), and will there- 

 fore not be repeated here. Having completed the formation of the 

 egg cavity, the female withdraws her proboscis and turns end for 

 end. She depresses the tij) of her abdomen and locates therewith the 

 opening to the cavity by feeling or scraping around. In a majority 

 of cases the opening is readily found, but sometimes it is not. Then 

 the female seems often to lose all sense of locality, but continues 

 scraping with the tip of her abdomen. If she is still unsuccessful, 

 she turns and continues the search by means of the antenna?, just 



