270 



PEINCIPLES OF PLANT-TERATOLOGY. 



willow (Salix fragilis)* were examined, in which the 

 bracts and pistil were enlarged and virescent, and 

 slight proliferation of each flower had occurred. But 

 the striking feature about all, or the majority of the 

 flowers, was the fact that, all round the base of the 

 ovary, on the floral axis above the level of the bract, 

 were great numbers of separate carpels, occurring 

 either singly, or aggregated in places into distinct out- 

 growths, their distribution being altogether irregular,, 

 and the individual carpels varying in age and size. 

 They must be regarded as representing masses of 

 rudimentary flowers which have not been able to 

 develop in the normal rigid way owing to the excessive 

 vigour of the tissue-growth of the axis ; hence they are 

 also adventitious and not axillary. 



On some woody twigs of the same species the entire 

 catkins appeared to be represented solely by dense 

 agglomerations of these rudimentary flowers which 

 were arising endogenously from the inner tissues of 

 the cortex, and breaking through the bark at four 

 different places, causing as many longitudinal slits in 

 the twigs. The endogenous formation of flowers is a 

 hitherto unheard-of phenomenon and is one of the very 

 rarest abnormalities to be met with. 



These hypertrophiecl catkins are probably due to the 

 irritation set up by aphides or mites. 



BIBLIOGRAPHY. 



Baillon. — "Note sur VHordeum trifurcatum Jacq." Bulk 



Soc. bot. Fr., tome i (1854), pp. 187-189. 

 Henslow, J. S. — " On the Awns of Nepaul Barley (Hordeum 



cceleste, var. trifurcatum and segiceras)" Hooker's Journ. 



Bot., vol. i (1849), pp. 33-40. 

 Hoffmann, H. — " Culturversuche." Bot. Zeit., Jahrg. xxxv 



(1877), p. 267, pi. iii [Hordeuin]. 

 Irmisch. — " Beschreibung einer merkwiirdigen Missbildung 



von der Bluthe von Hordeum hymalayense trifurcatum 



H.Monsp." Linnsea, vol. xiii (1839), pp. 124-128, pi. iv. 



* Sent by Mr. Hugh Watt, of Hampstead. The present writer collected 

 specimens of the same abnormality on some trees of this species at Chingford, 

 also of this species and of S. alba and S. viminalis on Hampstead Heath. 



