MR. C. BAR-Wiy OX SPECIFIC DIFFKRENCES IN PRIMULA. 441 



The evidence, however, on the first head is of little value; for, 

 dimorphism not being formerly understood, the seed-bearing plants 

 were in no instance * protected from the visits of insects ; and 

 there would be almost as much risk of an isolated Cowslip, or of 

 several Cowslips if consisting of the same form, being crossed hy 

 a neighbouring Primrose and producing Oxlips, as of one sex of a 

 dioecious plant, imder similar circumstances, being crossed by the 

 opposite sex of an allied and neighbouring species. Mr. H. C- 

 Watson, a critical and most careful observer, made many experi- 

 ments by sowing the seeds of Cowslips and of various kinds of Ox- 

 lips, and arrived at the following conclusion f, namely, " that seeds 

 of a Cowslip can produce Cowslips and Oxlips, and that seeds of 

 an Oxlip can produce Cowslips, Oxlips, and Primroses." This con- 

 clusion harmonizes perfectly with the view that in all cases, when 

 such results have been obtained, the unprotected Cowslips have 

 been crossed by Primroses, and the unprotected Oxlips by either 

 Cowslips or Primroses ; for in this latter case we might expect, by 

 the aid of reversion, which notoriously comes into powerful action 

 with hybrids, that both parent forms in appearence pure, as well as 

 many intermediate gradations, would be produced. Nevertheless 

 the two following statements offer considerable difficulty. The 

 Bev. Prof. Henslow J raised from seed of a Cowslip growing in 

 his garden, various kinds of Oxlips and one perfect Primrose ; 

 but a statement in the same paper perhaps tlirows liglit on this 

 anomalous result. Prof. Henslow had previously transplanted 

 into his garden a Cowslip, which completely changed its appearance 

 during the following year, and now resembled an Oxlip. Next 

 year again it changed its character, and produced, in addition to 

 umbels, a few single-flowered scapes, bearing flowers somewhat 

 smaller and more deeply coloured than those of the common Prim- 

 rose. From what I have myself observed with Oxlips, I cannot 

 doubt that this plant was an Oxlip in a highly variable condition, 

 almost like the famous Cj/fisus AdamL This variable plant was 

 propagated by offsets, which were planted in different parts of the 



One author states in the * Phjtologist ' (vol. iii. p. 703) that he covered with 

 bell-glasses the Cowslips, Primroses, &c. on which he experimented. He speci- 

 fies all the details of his experiment, but does not say that he artificially fertilized 

 his plants ; yet he obtained an abundance of seed, wliich is simply impossible. 

 Hence there must have been some strange error in these experiments : possibly 

 the bell-glasses may have been removed by some one during the night. There- 

 suits of these experiments may be passed over as valueless. 



t Phytologist, n". pp. 217, 852; iii. p. 4:5. 



X Loudon's Mag. of ^'at. Hist. iii. (1830) p. 401*. 



1-12^'N. PRoc. — bota^hT, vol. I. 2 a 



