850 



dissection, it should not be difficult to descry the lowest portion of 

 the pollen-tube inserted into the micropyle, at the period immediately 

 succeeding the fecundation of the ovule. 



An argument which has been used with far more limited applica- 

 tion by Mirbel and Spach, may not be iri'elevant here. "Pour defen- 

 dre avec succes [cet] opinion, il faudrait prouver non seulement que 

 le boyau pollinique acquiert [souvent] une longueur demesuree, mais 

 encore qiCil est done dhm sens particuUer, a la faveur duquel il se 

 dirige^ * On the latter point, at least, it may be also said, without 

 danger of contradicting those high authorities, — " Jusqu'a ce jour, 

 cette prenve n'a pas ete produite : " and when it is considered that in 

 numberless cases the micropyle is not directed towards the placenta, 

 but turned away from it, and thus placed in the most difficult and un- 

 likely position for access on the part of an organ not endowed with 

 intelligence, it might not be absolutely presumptuous to doubt whe- 

 ther these great observers may not, for once, have been misled by il- 

 lusory appearances ; or at least it may not be unpardonable to ask for 

 additional evidence in support of the statement, to establish it as a 

 general rule. 



2 1 3 



Myosotis pahistris. 



Fig. 1.— Longitudinal section of the base of a flower, showing two of the rudimentary nu's (o a) at the 

 base of the style [b). 



Fig. 2.— One of the rudimentary nuts more highly magnified, a. The pericarp, b. The style, e. The 

 micropyle of the ovule. 



i"ig. 3.— A nut, half ripe, showing the altered position of the micropyle (e), no longer directed towards 

 the base of the style (b), but in juxtaposition with the summit of the pericarp (a), d. The embryo. 



The instances in which the micropyle is presented to the placenta, 

 or rather, where it is placed in apposition with the base of the con- 



* Annales des Sciences Nat. tome xi. p. 212. 



