94 MR. J. SCOTT ON THE FUNCTIONS AND STRUCTURE OF THE 
tively to the heteromorphie unions in P. Auricula exceeds more 
or less that of each of the four hybrid unions of that species. 
These are most formidable facts for those who look upon sterility 
as a special endowment to prevent the blending of organic forms. 
Utterly irreconcileable, indeed, with such an idea, they, on the 
other hand, plainly show “ that sterility is not a specially acquired 
or endowed quality, but is incidental on other acquired and little- 
known differences,” as Mr. Darwin has very properly urged. 
Taste IV.—Pure and hybrid unions of P. Auricula. 
TMEHETBT 
geo gdbiíim»tuz8 
3c zz IS SS as) as 
$ o.9 SEIPRIEIPRIEIPE: i 
= BS vua, NEM le ES 
LM Her Be 
5pÓSRIEÓSO|BSÓOS EST 
oas efle Db 
SEES CYSTS ET ES 
ACER ASS AS BAAS 
The heteromorphic unions relatively to 100 | in d 
the homomorphie unions of P. Auricula pu "Y | 
The short-styled homomorphie union of | a 
P. Auricula by pollen of P. viscosa re- 100 | 96 | 100 16 
latively to the pure unions of the former | 
The long-styled heteromorphie union of | 
P. Auricula by pollen of P. hirsuta re- 100 65 100 23 
latively to the pure unions of the former | | 
The short-styled homomorphie union of | 
P. Auricula by pollen of P. hirsuta re- 100 | 49 | 100 | 3I 
latively to the pure unions of the former | | 
The union of long-styled P. Auricula by | | | 
pollen of the non-dimorphic P. ver- | | | 
ticillata relatively to the pure unions of E | Sé un | = | 
"8 ` | | | 
In Table III. I have given the results of all my successful ex- 
periments on the hybridization of Primula Auricula: it is neces- 
sary, however, for the more complete elucidation of the influence 
of dimorphism on hybridism, that I also subjoin a few instances of 
my unsuccessful trials, in so far as connected with the reciprocal 
unions of those already given. First, then, by referring to Table 
IV. we see that the short-styled homomorphie unions of P. Auri- 
cula by pollen of P. viscosa are highly fertile; nevertheless I have 
completely failed to fertilize reciprocally P. viscosa by pollen of 
P. Auricula. I also failed to effect an heteromorphic union be- 
tween these species: my experiments, however, in this case were 
limited to the long-styled P. Auricula by pollen of short-styled 
P. viscosa. Again, secondly, the long-styled heteromorphie and 
short-styled homomorphic unions of P. Auricula by pollen of P. 
