1865.] Botany and Vegetable Physiology. 455 



the nectary and its appendages is prevented. M. Godron made ex- 

 periments with the flowers of Diclytra, so as to compress one of the 

 petals at the base during its development, and he thus rendered it 

 like Fumaria with a single spurred petal. 



In Diclytra and Adlumia the spurs develop at a later period than 

 in Fumaria, and in such a way that the raceme in elongating separates 

 the flowers from each other, and allows the free and equal formation 

 of spurs. 



The regular form sometimes continues in the Fumaria and Cory- 

 dalis. M. Godron has seen Corydalis solida assuming a pelorian 

 form by two or even four petals becoming spurred or calcarate. The 

 flowers in this case are sterile. 



Inflorescence of Cruciferm. — Bracts are generally wanting in the 

 racemes of Cruciferae. In some of the characteristic species we find 

 bracts occasionally in the lower flowers. In Sisymbrium supinum, 

 L., all the flowers are produced with a pinnatifid bracteal leaf, and 

 the same is the case with Sisymbrium hirsutum, Lagasc. 



Brassica oleracea has been seen with large oblong bracts in con- 

 nection with its lower flowers, while smaller bractlets occurred at 

 the upper part of the raceme. Similar phenomena have been ob- 

 served in Erysimum cheiriflorum, Wallr. Arabis Turrita, L., Hes- 

 peris matronalis, L., Bunias orientalis, L. Sometimes the lower and 

 middle part of the inner face of the bract becomes united to the base 

 of the peduncle. This has been noticed in Iberis sempervirens, L., 

 and in other Cruciferous plants. Sometimes when the bracts are 

 completely wanting, there are traces of the decurrence of leaves at 

 the base of the naked peduncle. 



Godron says that, 1st, the quaternary type, with two rows of 

 stamens, is the normal condition of Cruciferas ; 2nd, that the absence 

 of bracts, and the greater or less flattening of the peduncle ; the more 

 or less depressed form of the flower bud ; the slight irregularity of 

 the calyx, the absence of two stamens in the outer verticil of the 

 androecium, and often of the two glands on which they rest, and 

 finally the abortion of two carpellary leaves, are determined by a 

 pressure which is exercised from within outwardly on the flowers of 

 Cruciferae ; 3d, this pressure is owing to the accumulation of flowers 

 which are developed in great numbers at the summit of the Inflo- 

 rescence in its corymbiform state, and which are naturally restrained 

 or hindered in their evolution, as well as to the resistance which is 

 presented to this expansion by the accumulated leaves which surround 

 the inflorescence at its origin. 



