510 MacDoucaL: SoME CORRELATIONS OF LEAVES 
internodes, the basal one of which measured 14 mm. . Two 
branchlets were produced at the next node below on the newly- 
formed portion of the main branch, which showed two and three 
internodes and were 10 and 15 mm. long respectively. The 
third internode below produced two branchlets 6 and 12 mm. 
long and composed of two internodes. 
The lateral branchlets of the main branch showed less total 
growth and also less marked development of the lateral buds cor- 
respondent to the general habit of the normal. Activity of the 
vegetative points on the defoliated and normal branches had 
practically ceased on June 15, the mutilated branch showing no 
prolongation of the period. The departures from the normal 
structure of the stem were fairly similar to those described in 
Prunus, Chlorophyl was quite as profusely developed in the 
normal as in the treated branch, however, and was found in the 
medullary rays in great abundance. 
The above results are found to agree in the main with those 
of Boirivant, who practiced defoliation and delamination and noted 
the effect upon stems and upon petioles of Fada vulgaris, Sa- 
rothamnus scoparius, Genista tinctoria, Lathyrus odoratus, Cheno- 
podium album, Atriplex nitens, Linum usitatissimum, Galum 
Cruciata, Asparagus officinalis, Robinia Pseudacacta, Arachis 
hypogaea and Ailantus glandulosa.* It is to be noted, however, 
that the epidermal tissues in my material showed enlargement in 
the tangential axis, and one or two other minor differences appear- 
Boirivant’s studies included a consideration of the anatomy of the 
petioles of leaves of which the laminae had been cut away, and in 
these organs he found an exaggerated production of chlorophyl, 
modifications of the cortical tissues consisting of added differentia- 
tions of palisade tissue, and enlargement of the vessels and more 
lignification of the tracheids and pith. I am not able to find that 
he noted the effects of the treatment upon the stipels of Robinia, 
or made observations upon the reaction of the hypopodium 
especially. 
The observations of Braun also extend over the matter of the 
effect of delamination on stems. His observations included 
Cee amt 
aia 
*Boirivant, A. Recherches sur les organes de remplacement chez les plantes- 
Ann. Sci. Nat. Bot. VIII. 6: 309-400, 1897. 
