[1]

1864.

SCOTT'S PAPER

Page 106 to 108. Red cowslip by variation has become non-dimorphic, and with this change of structure has become much more productive of seed than even the heteromorphic union of the common cowslip. Page 91, 92, similar case with Auricula; on the other hand a non-dimorphic variety of P. farinosa (p. 115) is less fertile. These changes, or variations, in the generative system seem to me very remarkable. But far more remarkable is the fact that the red cowslip (p. 106-8) is very sterile when fertilising, or fertilised by the common cowslip. Here we have a new "physiological species." Analogous facts given (p. 98) on the crossing of red and white primroses with common primroses. It is very curious that the two forms of the same species (p. 93, 94, 95, & 117) hybridise with extremely different degrees of facility with distinct species.

He shows (p. 94) that sometimes a cross with a quite distinct species yields more seed than a homomorphic union with own pollen. He shows (p. 111) that of the two homomorphic unions possible with each dimorphic species the short-styled (as I stated) is the most sterile, and that my explanation is probably true. There is a good summary to the paper.