868 
Journal of Agricultural Research 
Vol. XXXI, No. 9 
Buds from Royal apricot trees growing under the three following 
conditions on the university farm were compared: Lightly pruned 
and nonirrigated, heavily pruned and irrigated, lightly pruned and 
irrigated. Each tree grew near and under the same cultural treat¬ 
ment as the pears described above. All were typical except the 
lightly pruned and irrigated tree, which apparently lacked vigor. 
Few apricot trees could be found at the relatively high elevation in 
Eldorado County. The tree selected was thought to be a specimen 
of the Royal variety. It was an aged tree growing at an approximate 
elevation of 2,200 feet, and had received little or no pruning and 
but limited irrigation. 
All trees in the experiment were under clean culture, with the 
exception of the apricot last mentioned. 
Collections were made on or near July 10 and 20; August 1, 10, 
and 20; September 1 and 15; October 1 and 15; and November 1 
from all trees except those in Eldorado County, where there were 
none taken July 10. In addition to these, samples were taken from 
all the trees at the university farm on December 1, and from the 
lightly pruned and irrigated pear tree and from the heavily pruned 
and irrigated apricot tree at intervals of from one to two weeks from 
January 1 until blossoming time. 
METHODS 
All buds were collected from fruit spurs not more than 3 inches 
long, and from all sides of the tree. About 30 buds were taken from 
each tree at each collection. Since fruit buds only were desired, 
the largest, plumpest pear buds and double and triple collateral, 
buds of the apricot were taken. In the case of the apricot, contrary 
to the published inferences of Gourley (S), 3 Bailey (1 p . 88) and others, 
the middle bud is not always a leaf bud. Many of these collateral 
buds were sectioned as a unit and all found to be flower buds. 
Upon removal from the tree, the buds were immediately put in a 
formalin-alcohol killing and fixing solution, in which they were kept 
until ready to use. in later collections the outside scales were re¬ 
moved before killing, and with pears even the top part of the indi¬ 
vidual flower buds was cut away to eliminate the abundant hairs 
which hung on the knife edge of the microtome and prevented the 
proper ribboning of the paraffin mounts. 
The major part of the sectioning was accomplished by the paraffin 
method as described by Chamberlain ( 2 ). The outstanding depar¬ 
tures from Chamberlain’s methods were less gradual dehydration 
and the holding of the material in the alcohol solutions for a shorter 
time. Safranin dissolved in alcohol and gentian-violet in clove oil 
proved to be the most satisfactory combination stain. Light green 
with safranin and Delafield’s haematoxylin with safranin were 
tried but found less useful. Haidenhain’s iron-alum haematoxylin 
proved to be useful as a nuclear stain but difficult to handle. Coplin 
jar tops, inverted and the inside surface coated with a thin film 
of glycerine, proved useful as embedding molds. Sections from 5 to 
12.5 microns in thickness were cut. The thicker sections proved 
more satisfactory for photographing gross morphology. The thinner 
3 Reference is made by number (italic) to “Literature cited/’ p. 882. 
