ENCLOSURE TO PART III. 
Mr. DUCKER said that he harvested every plant separately and 
took the lint and seed characteristics. 
Mr. WOOD asked the opinion of the Section on the possibility of 
adopting a standard method of sampling and measuring by which the 
purity of a strain could be expressed numerically. 
Mr. PARNELL said that the limiting factor with him was jassid 
resistence and the necessity for a resistant strain was so great that he 
was propagating one for distribution, which, although by no means 
uniform, was decidedly better than any other obtainable. This would 
immediately be followed by a more uniform type. He selected 12 
plants from every row, whereas Mr. Ducker used every plant and Mr. 
Nye 15 plants from each progeny row. 
Mr. DUCKER considered that periodic pickings from the progeny 
rows were of little value, but Mr. Parnell considered that this did 
show up differences. 
Mr. NYE wanted to know if a standard size of plot for variety 
trials could be adopted. 
Mr. PARNELL considered that we had not yet sufficient 
experience. 
Mr. CAMERON suggested that rows were just as suitable as plots 
and were much easier to handle. 
Mr. NYE said that in Uganda he used rows inside the plots; the 
edge effect was two plants deep. 
After some discussion 
It was decided to call attention to the possibility of 
inaccuracy in comparing strains. 
Mr. PARNELL, as a result of the discussion, asked whether 
anyone had experience as to whether in comparing strains the spacing 
methods adopted were likely to affect comparative results—two feet 
was his standard. 
Mr. DUCKER replied that he had only made casual observations 
on this point, but it had been noticed that one particular strain was 
intolerant of wide spacing. 
5. Tue Position win REGARD 10 CROSSING. 
Mr. NYE asked for information regarding crossing; he found it 
very difficult to get results. 
Mr. PARNELL said that crossing ought to be valuable, but in 
practice it did not appear to be so. At present he was crossing 
Cambodia with another type in order to combine jassid resistance with 
other desirable qualities, but it appeared as if this would be obtained 
by selection. Selection is obviously the first thing, and if crossing is 
gong to be of any value an early start should be made at it, for it 
takes a long time before any results are achieved. 
Other members of the Section expressed their views on this 
question, the general opinion being that, although no very valuable 
results had yet been obtained from crossing, this was probably due to 
the magnitude of the work necessary in bringing it to a successful 
conclusion. 
6. ExcrnaNes oF Strains BErwrEN DIFFERENT TERRITORIES. 
Mr. KOCH thought it would be very useful if the Agricultural 
Departments of the African Territories could keep in touch with each 
other as regards new strains. so that when any good strain was 
149