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Igto] PENNINGTON—LONGITUDINAL COMPRESSION 263 
during the summer. The growth was very unequal in different 
stems. Some of them increased in size three or four times as much 
as others, which grew under apparently the same conditions. 
This is not an uncommon. occurrence, however, among shoots 
which spring from old roots. 
Careful comparisons did not show any greater increase in growth 
or thickness of stem in the experimental plants than in control 
plants. On the other hand, some of the experimental stems had 
smaller diameters in the compressed portion than control stems. 
This diameter in three stems was less than the diameter of the 
same stem above the compressed part. Although this difference 
is normally not infrequently noticed in this species, it was rather 
more striking than usual in these plants. Cross-sections were 
prepared from experimental stems, control stems, and stems which 
had not even been tied to stakes. No differences, however, could 
be seen between any of them. 
LOCUST SEEDLINGS 
In order to obtain woody stems of more nearly uniform size, 
seedlings of locust were grown in the greenhouse and transplanted 
into the garden as soon as the weather became favorable in the 
spring. Of about 100 which were transplanted, only 30 were con- 
sidered suitable for experimentation. These were prepared in the 
usual way and kept under experimental conditions until growth 
had ceased, about October 15. In the greenhouse, some of the 
seedlings grew to a height of 15-20 cm.; their stems, however, were 
very weak. When they were transplanted, they were bent nearly 
if not quite to the ground by every little breeze, which could scarcely 
bend locust sprouts which had come up in the garden. In two or 
three weeks’ time, however, these slender seedlings, although they 
had grown but little in height, had become strong enough to with- 
Stand ordinary winds. Some of these slender seedlings were tied 
to stakes to prevent their being whipped about by the wind. Twe 
or three weeks later, when the stakes were taken away, the plants 
were still unable to support themselves against a light win 
This series was kept under the best conditions for siete The 
plants were watered frequently during the dry season and protected 
