SCIENTIFIC COMMITTEE, OCTOBER 25. 



ccli 



Fasciation in Rose. — Mr. W. Patterson sent a fasciated branch of 

 Hose from St. Vincent, W.I. He remarked that it had been, taken 

 from a bush which had been severely cut back. In his experience, 

 fasciation was somewhat rare in Eoses as compared with many other 

 plants. 



Pear with lateral proliferation. — Mr. Eogers, of Falmouth, sent a 

 Pear which had produced a bud upon its side. This malformation is 

 rather common and is due to the fact that the fleshy part of the Pear 

 is a stem structure. 



Macaranga saccifera. — Messrs. Veitch exhibited, on behalf of M. 

 Louis Gentil, a plant of Macaranga saccifera, a iiative of the Congo dis- 

 trict, belonging to the EujpJwrbiaceae, and possessing very curious 

 saccate growths of the nature of stipules: a pair at the base of each 

 leaf. The Committee, on the proposal of Mr.* Bowles, seconded by 

 Mr. Hales, unanimously recommended the award of a Botanical Certifi- 

 cate. 



Plant breeding, &c. — The Eev. Prof. Henslow made some remarks 

 upon the Mendelian phenomenon of segregation. He first drew atten- 

 tion to the fact that dissociation of the characters of the parent plants 

 crossed — when the dominant offspring (Fj) was self -fertilized and bore 

 offsprings usually like each parent (F2) — often appeared in the first 

 cross, so that this (F J was intermiediate in characters, as of that of 

 Primula sinensis ' Crimson King, ' with a white (Star) ' Lady ' variety 

 (Bateson's " Mendel's Principles of Heredity," PI. vi.). Mendel's dis- 

 sociations appear to be a previously unknown instance. Prof. Henslow 

 gave as examples among hybrids the two species of Petunia with a purple 

 or violet and white flower respectively, the offspring of which are mostly 

 striped. Cytisus Admni is another case. Of crosses with floral or 

 fruit dissociations he mentioned Rhododendron (Azalea) indicum, the 

 York and Lancaster Eose, Sweet Williams, Chrysanthemums, Orchids, 

 &c., and the fruit of Eed and White Currants. Another cause of dis- 

 sociation arose when naturally compound colours as orange and j)urple 

 are crossed with a white variety. Thus the orange Abutilon Darwinii 

 and Rhododendron javanicum have supplied reds and yellows. Now the 

 question arises — ^When one parent is quite invisible and recessive in F^, 

 why is the other dominant? Judging from the examples given in Mr. 

 Bateson's work, the answer is that the dominant characters are mostly, 

 if not always, those representing the original specific type. Thus tall- 

 ness of stems, round and yellow seeds, are dominant in the kitchen Pea. 

 The purple and flat standards of the Sweet Pea are specific and domi- 

 nant. In fruits, the normal and prickly forms of Ranunculus arvefisis 

 and of Datura are dominant. If, therefore, the species be known as the 

 earliest varie^ies, such may be expected to supply the dominant char- 

 acters. 



He then read the following note on the influence of starvation on sex. 

 In the note on this subject, read September 13 (p. ccxlvii), it was men- 

 tioned that in one of the 3^-inch pots there wete 73 seedlings of Mer- 

 curia.lis annua. Of these, 39 proved to be males and 10 females on 



