396 BOTANICAL GAZETTE [ NOVEMBER 
In this vicinity there is found on S. sericea a leaf gall, pyri- 
form or globular in shape, about 1% in diameter, enclosing a 
single larva of a species of saw-fly (Vematus Salicis-pomum 
Walsh), kindly identified for the writer by Miss Mary E. Murt- 
feldt of Kirkwood, Missouri. The same has been observed on 
some of the hybrids and on var. vestita, on two trees of the 
latter in extraordinary abundance. Not a single one have I 
seen on S. cordata, or on specimens approaching near to it, 
though growing side by side with those just mentioned! This 
fact is of the greatest importance, because it unites with a num- 
ber of other facts showing that var. vestifa is closer to S. sericea 
than to S. cordaia. 
Besides the transformations above noticed, the tendency t 
abnormalities has to be added. ‘Complexity of inheritance, 
like complexity in a chemical substance, gives instability to the 
offspring and thus liability to variation in the offspring.” * Te 
adnateness of filaments to the extent of 40 per cent. in hybrids, 
and 73 per cent. in var, vestita as shown in the summary, May be 
one of these abnormalities, but may be the usual character of S. 
cordata, though not heretofore noticed by any writer consulted. 
Related to this are cases where partly adnate filaments divide, 
making four filaments, each with a single anther cell; or the 
two filaments free, one of them dividing, thus making three 
stamens; or but a single stamen; or single stamen divided, each 
half filament bearing a cell; or the two stamens wholly united, 
bearing a double anther of four cells. More rare than the fore- 
going is the doubling of the ovary. There are also a ie ae 
of strictly two-lobed styles, but more common are eo 
presenting both two and four-lobed styles on the same — 
In var. vestita the style is occasionally undivided, pres 
merely circular stigma, or with very indefinite divisions. 
size of these hybrids may seem surprising, but all of our fo : 
of S. cordata, as well as S. sericea, exceed the limits, of the boo : 
Pure S. sericea attains the height of 15%, with a diameter of abe 
though usually only 5 to 10%, As to our S. cordata, it 18 impor 
? LECONTE: Evolution, 218. 
