64 [ASSEMBLY _ 
1. The potatoes planted in the garden were designed to be dug dur- 
ing growth for the purpose of studying into the underground processes. 
It would be confusing, and seems unnecessary to enter into a state- 
ment of the dates of planting and the full particulars noted at the 
various dates of examination. Suffice it to say that the variety used 
was the Early Rose. The system of planting included level culture, 
_ hil culture, ridge culture ; single eyes cut small, and single eyes cut 
as large as. possible: half potatoes, whole potatoes, seed ends, stem 
ends; potato shoots, potato peelings. - 
Some rows received ordinary cultivation, other rows excessive culti- 
vation, and still other rows no cultivation at all. One plat was covered 
with straw, the seed being laid on the ground; another plat covered 
with four inches of sand, and another with six inches of sand, the seed 
being laid on the ground ; another plat mulched in the intervals of 
high ridges, which received the seed; one potato plant hilled to the 
depth of four feet two inches, etc, In complementary trials potatoes 
from which the eyes had been deeply removed were planted ; other po- 
tatoes which had been peeled; leaves slipped in the cold frame and 
then when rooted removed to the open ground; potatoes which had 
started into growth and then the growing shoots rubbed off; potatoes 
whose eyes were injured by scalding ; potatoes from which the central 
portion had been removed ; single eyes split into many pieces, etc. In 
addition, before the ground was fit for planting, potato eyes and whole 
potatoes were started into growth in glass vessels in the house, and the 
growth and development carefully measured and commented upon. 
Among the first observations, which were yielded from the digging up 
the growing plants, were the great diversity in the tuber formation of 
adjoining hills. In one hill when small tubers were already formed, in 
an adjoining hill there would be no appearance of tuber; in one hill, 
perhaps, numerous tubers, in another hill but few; in one hill large, 
in another small tubers. With all this variation, which in part held 
true during the whole period of growth, there seemed absolutely no 
relation between the appearance of the green tops and the formation 
of tuber; large growth of top did not necessarily indicate abundance 
of tuber, nor did small growth of top indicate sparseness of tuber. In 
the recognition of these divergences, it seemed essential to seek 
for a cause, by digging series of plants and observing whether 
there could be seen any common character which should be 
coincident with abundance or scarcity, earliness or lateness of yield. 
' In the grouping of the likenesses together, the whole plant being 
brought under study, we very soon noted that there was a relation be- 
tween the character of the seed cutting and the yield. Acting upon 
this clue, we noted that single eyes produced larger yield and greater 
evenness of yield, together with superior quality over cuttings which 
included many eyes, and that while small cut eyes were inferior to 
large cut eyes in general, yet that the depth to which the cutting was 
made into the seed potato exerted a strong and undeniable influence 
on the crop. We now had a suggestion for further investigation, and 
it was pursued in thismanner. Whole potatoes were sliced lengthwise 
so that the cut should bisect as many eyes as possible. ‘These slices 
were then stained with a carmine solution. We thus were enabled to 
note that the potato tuber had a certain visible internal structure, 
