Experiments carried out in 1904 (Series II). 
In June of 1904 the castration experiments were continued in 
exactly the samme manner as in 1903. 
(1) H. pilosella L. from the same clump as Series I4. June 
11th 1904; 4 heads were castrated; the seeds were ripe at July 1*; 
sown') immediately; germinated; planted out in September 1904; 
flowered and fruited copiously in June—July 1905; discarded (No. 51). 
(2) HA. substoloniflorum Nag. & Pet., f. longipilum (determ. 
Dahlstedt), growing in a lawn in the Garden (near the Observa- 
tory). June 11% 1904; 15 heads were castrated; the seeds were 
ripe at July 4b, sown immediately; germinated; planted out in 
September; flowered and fruited copiously in June—July 1905. 
(No. 53). 
(3) H. flagellare Willd. (revis. Dahlstedt), growing together with 
the foregoing. June 11tk 1904; 20 heads were castrated; some of 
them did not develop; the seeds of the developed heads ripe July 
Ath; germinated and planted out as above; flowered and fruited 
copiously in June—July 1905 (No. 52). 
(4) H. pilosella L., growing in a lawn near the Taxus-shrub- 
bery in the Garden; the specimens bear ripe fruits, but some of 
them are empty. June 11% 1904; 10 heads were castrated, but did 
not develop well; June 20th, all faded. New castration gave no 
result, as the grass of the lawn was cut. 
Experiments carried out in 1905 (Series VI). 
(1) A. venosum L. A specimen in our herbarium, collected 
in Sayre, U.S. A., 1903 by Mr. W. C. Barbour, had ripe seeds, 
which were sown in July 1904 and germinated; in May 1905 
they were planted out and flowered copiously from the end of 
June (No. 54). — July 2rd 1905; 10 heads were castrated, but no 
full seeds were developed. The heads which were intact, gave 
ripe seeds (93 barren fruits to 91 full). Again in September a 
good many heads were castrated, but with the same negative 
result; at that time the intact heads gave more barren and fewer 
full fruits (855 barren to 128 full). The full fruits have germi- 
nated in 1906. 
(2) H. Gronovii Willd.; seeds obtained from the Missouri Bo- 
tanical Garden, sown in the spring of 1905, germinated, trans- 
1) Always in baked soil. 
