392 BOTANICAL GAZETTE [MAY 
this insufficient development of the chlorophyll, whereas the 
velutina is dark green. The main interest of these crosses lies in 
the fact that their /aeta do not give a uniform progeny, but split 
into laeta and velutina, exactly as in the case of the hybrids of 
O. Hookeri and O. Lamarckiana (5). The velutina constitute con- 
stant races in both instances. 
I made the cross O. Cockerelli XO. grandiflora twice, once in 
1914 and once in 1915. They yielded 58 and 64 offspring, among 
which 33 and 28 per cent were Jaeta and 67 and 72 per cent velutina. 
These twins resembled those of O. CockerellixO. Lamarckiana, but 
- some of the Jaeta had a yellowish green foliage and were more or 
less weak in constitution for that reason. The Jaeta had broad 
leaves (4.515 cm.), whereas those of the velutina were narrow 
(315 cm.), and the same difference prevailed between the bracts 
of the spike. This character was very conspicuous on the beds, 
especially when compared with the cultures of the next generation. 
Moreover, I had a lot of O. syrticolaXO. grandiflora at the same 
time and found the types of both twins to be essentially the same 
as in this cross. 
In the second generation the velutina were uniform and repeated 
the characters of the parent. The culture embraced 70 flowering 
plants. They were a strikingly uniform lot, and made the dis- 
tinction of the two types in the first generation as well as among the 
progeny of the laela quite easy. These latter consisted also of 
70 flowering specimens, which were counted in July, shortly before 
the opening of the first flowers. They gave the percentages shown 
in table ITI. 
O. grandiflora XO. Cockerelli—Apart from the fact that all the 
hybrids are of a normal green color, this cross simply repeats the 
reciprocal one. I crossed two specimens in 1914 and had the first 
generation of 80 individuals in 1915. They showed in July 52 pet 
cent /aeta and 48 per cent velutina, with the same differences as pre- 
viously given and the same resemblance to the twins of O. syrticola 
x grandiflora. About one-half of the plants flowered, the flower 
buds of the /aela being relatively thin, but those of the velutina 
thick (5X20 mm.) and hairy. The second generation gave a uni- 
form lot of 70 flowering plants for the velutina and a dimorphic 
