208 
muck and sifted manure, well mixed. One tuber was placd in each 
pot. The remaining three, Nos. 7, 8 and 9, were planted in a simi- 
lar manner, in sifted lake sand of rather coarse texture. 
By March 30, 1885, the more advanced stems of the plants grow- 
ing in both the potting soil and sand had formed flower buds. The 
planted tuber, from one pot containing the sand, and one containing 
the potting soil, was removed and the dry matter determined. 
On April 29th, the planted tuber from a second pot containing 
each of the two soils was removed and dried, and on May 29th, the 
remaining planted tubers were removed, but unfortunately the one 
from the sand was somewhat decayed, so that its weight could not 
be determined. 
The results obtained appear in the following table, in which the 
weights are given in grammes. 







E go% | 53 
3 g z -2s | 22 
5 a 2 38) hE 
5 : g% s 38m | oS. 
ty i aa = 33'S 2) Sp 
3 ax Pg aoe 9g 
E Be eo ne oi a sys 
5 oe mH £ 5e> 5S 0 
A = a A ay aw 
1 282.5 gTs. 73.3 gYs. 25.444 
2 OULee en (cor eet 23.940 
3 aid ey yk Blaitw $8 22.258 
4 ACOs Mar. 30 AT. Bane | 17.909 2d. 
rf R10. eee Reais A525 1% 15.638 34, 
4) 323.4 ‘ Apr. 29 26.4 ** 8.016 62. 
8 ROD ee FRUSS 16 SUE 5.448 ig 
6 oer ny, May 29 G7 es 2.117% G1; 
As the tubers were not equal in weight, we are able to compare 
their matter only as percentage. 
The average dry matter of Nos. 1, 2 and 3, on Dec. 23d, was 22.- 
880 per cent., and Prof. Johnson gives as the average of nineteen 
analyses of various varieties 24 per cent. In computing the percent- 
age of loss of Nos. 4 to 8, inclusive, we assume that those tubers origi- 
nally contained 23.880 per cent. of dry matter. 
It appears therefore that tuber No. 4, grown in potting soil, lost 
from Dec. 23rd, the time planted, to March 30th, about 25 per cent. 
of its dry matter, while No. 7, grown in sand, lost in the same time, 
about 34 per cent. Tuber No. 5, grown in potting soil, lost from 
the time planted to April 29th, about 62 per cent. of dry matter, and 
No. 8, grown in sand, about 77 per cent. Tuber No. 6, grown in 
potting soil, lost, from the time planted to May 29th, about 91 per 
cent. of its dry matter. 
It thus appears that the matter of the tuber continued to be ab- 
sorbed by the growing plant, during more than five months of growth 
in the greenhouse, at the close of which time almost the entire sub- 
stance of tuber No. 6 had been taken up. 
