556 EXPEKIMENT STATION RECOKD. 



comi3aratively very difficult to propagate; whereas Newman and Chaljot are com- 

 paratively easy." 



In the comparison of stocks, Americana gave the largest average total of trees in 

 each lot, the tallest trees, and considerably the largest number of merchantable 

 trees. This is considered the most striking feature brought out by the experiment. 

 Heretofore Americana stocks have come into use only in the Northwest, and there 

 because they are believed to be extremely hardy. Mariannagave much the smallest 

 number of either total or merchantable trees. Going behind the averages in the 

 tables, the author summarizes as follows: 



"Stoddard — an Americana — did better on Americana roots than on any other, 

 though the Wayland stocks gave equal results as regards number of merchantable 

 trees and a greater average size. Green Gage seems to have done best on Wayland 

 stocks, and to have been a failure on Marianna^a stock on which it is often propa- 

 gated commercially. Chabot gave by far the best result on Americana roots, though 

 it has generally been supposed that Marianna and Peach stocks were specially con- 

 genial to the Japanese plums. Milton made the best showing on Wayland stocks, 

 while it was practically a failure on Peach. This last ijoint was very striking, and 

 came much in the nature of a surprise. Peach stocks have been supposed to be 

 suitable for all the plums of the Wildgoose type. Newman did best on Peach, which 

 is according to current opinion; but it gave second best results on Americana, which 

 is not in agreement with the nursery notions commonly held. It was poorest of all 

 on Marianna roots, though Marianna has often been specially recommended for 

 propagating all the Chicasaws. We therefore arrive at this important notion: That a 

 given variety does not do equally well on all stocks, and, vice versa, that a given stock 

 is not equally adapted to all varieties." 



Three of the best trees from each lot in these experiments were selected and planted 

 out in permanent form at the Vermont Station. Stoddard did best in every respect 

 on Americana roots. Green Gage on Wayland, Chabot on Marianna and Wayland. 

 Milton made a splendid growtli on all stocks l>ut Peach, and every tree on Peach 

 roots died. Newman did best on Wayland rof)ts and second best on Americana 

 roots. For the whole lot of trees, the general staten^ent is made that every lot on 

 Peach was inferior to the same variety on any other stock whatever. 



Further work in plum pollination, F. A. Waugh ( Vermont Sta. Bpt. IDOO, pp. 

 355-36:3, figs. 3). — In continuing this work (E. S. R., 12, p. 238), the results secured 

 in microscopic examinations and germination tests of the pollen of 44 varieties of 

 plums are recorded and discussed. The germination tests of the pollen were made 

 in sugar solutions varying in strength from 3 to 20 per cent. There seemed to be 

 little difference in pollen germination following the variations in strength of the dif- 

 ferent solutions, but on the whole the 5 per cent solutions gave the most uniform 

 results. The quantity of pollen produced and its germinating power were found to 

 vary greatly with the different varieties, as did also the size and plumpness of the 

 pollen grains. Pollen grains which to the eye presented a normal appearance were 

 sometimes lacking in protoplasmic contents. These irregularities appeared to be 

 unusually frequent with varieties of hybrid origin. No cause for the fluctuations of 

 the pollen grains in quantity, size, or viability could be assigned. It was concluded 

 that the germination of plum pollen is not readily influenced by ordinary external 

 conditions. The author summarizes briefly as follows: 



" From the standpoint of the practical plum planter, there seems to be only one 

 conclusion of consequence to be drawn from tlie study f)f jicjllen and i:)ollen produc- 

 tion; namely, that certain hybrid varieties, notably Wickson and Excelsior, probably 

 also Gonzales and others, cannot be relied on for the pollination of other varieties, 

 even though other conditions of simultaneous blossoming, etc., be fully met." 



Some drawings and notes are given on certain curious malformations occurring in 

 plum blossoms. 



