248 Ward. — On Relations between Host and Parasite 
inrolled palea terminating in two long slender papery teeth 
from between which the long slender awn arises. From base 
of ‘seed’ to apex of teeth 23-2.5 mm., the teeth themselves 
5-6 mm. Awn about 40 mm. Breadth of ‘ seed ’ about 
2 m. Colour dark-grey — mouse colour — with a purple cast. 
Rachilla long. The whole ‘ seed ’ and awn covered with 
minute forward asperities. Seedlings when four days old 
a spear about 2 mm. long, and much like the smaller and 
more quickly growing B. sterilis. 
In a week the pot-seedlings had a leaf projecting 2 cm. 
above the ground, the apex unfolding and the whole of a 
beautiful bronze-green. It showed five veins, and had stiff 
short hairs on the back, and was 2 mm. broad. The direction 
of rolling seemed to vary, but was usually such that the right 
edge comes over the left. 
In five days, forced plants in the intermediate pit had 
strong spears 5-10 mm. high. 
(3) Zeobromus , Serrafalcus. 
*Z>. secalinus , *B. velutinus , *B. mollis, *B. interruptus , 
*B. racemosus , B. commutatus , B. arvensis , B. brizaeformis , 
B. macrostachys. 
On comparing the ‘ seeds J of B. mollis , L., B. interruptus , 
Hack., B. arvensis , L., B. racemosus , L., B. commutatus , 
Schrad., B. secalinus , L., B. velutinus, it is clear that we have 
a series of very closely allied forms, bearing out Bentham’s 
contention that they should all be put as varieties or sub- 
species of one — B. arvensis. It is now usually conceded 
that B . arvensis , L., is not native in this country, and that 
B. secalinus with its variety B. velutinus , B. mollis with its 
variety B. interruptus , and B. racemosus with its variety 
B. commutatus , may be claimed as species l . In any case 
they are undoubtedly closely allied, and form the typical 
nucleus of the group or sub-genus Serrafalcus , formerly 
indeed separated as a genus from Bromus. 
On comparing a series of the germinated seedlings of these 
1 See Ascherson, Syn. d. mittel-europ. FL, for a critical survey of these relation- 
ships. 
