[37 & 38]

[Figure]

[38v]

90

Ipomoea

self-fertilised children is 74.85; or as 100 to 94. But in Pot IV one of the crossed plants grew only to a height of 15 1/2 inches; high and if this plant and its opponent are struck out, as would be the fairest plan, that the average height of the crossed plants exceeds only by a fraction of an inch that of the self-fertilised plants. It is therefore clear that a crossing of the self-fertilised children of Hero did not produce any beneficial effect; and it is very doubtful whether this negative effect result can be attributed merely to the fact of brothers and sisters having been united, for in the production of the ordinary intercrossed plants in of the several successive generations (as shown in the introduction, must often have been derived from the union of brothers & brothers and sisters must occasionally have been united (as shown in Chapt. I), and yet they intercrossed plants were always were greatly superior to the self-fertilised plants. We are therefore almost driven to the suspicion, which we shall soon see presently strengthened, that Hero has transmitted to its offspring a peculiar constitution adapted for self-fertilisation.

It would appear that the self-fertilised offspring descendant