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beak of its fruit, and on the other hand, that the teretiuscula has a 

 SERRATED membrane. Mr. Luxford says (Phytol. 922), when speak- 

 ing of the teretiuscula, that it has a serrulate wing. Smith describes 

 them both as having serrated beaks. These two plants are spoken 

 of indiscriminately as having their fruit hi/id or notched at the beak. 

 The two are also spoken of as having a dorsal wing upon the convex 

 side of their perigynia. By 'this it will appear that the difference of 

 the fruit of these plants is either very inconsiderable, or that the par- 

 ties who have attempted to describe them have never examined them. 



I have now given the ideas of some of our most eminent writers up- 

 on these plants, in nearly their own words, lest it should be said that 

 I have misapplied their meaning. I shall now impartially give the 

 results of my own observations on this subject; and by an exact exa- 

 mination of the plants themselves, will endeavour to find out which of 

 the above accounts, so diametrically opposed to each other, are the 

 most consonant to matter of fact. 



But before I commence I must lay down this general principle, 

 which I hope will not be denied, namely, that Nature is uniform in 

 all her operations, and does not recede from the rule laid down by the 

 Wise Disposer of all things, by making the same thing often two dif- 

 ferent methods. Therefore, if I were to find a central or winged line 

 on the convex side of the fruit of these plants, or find them with ser- 

 rated, CILIATED, or SERRULATED lateral margins in one instance, I 

 should expect to find them so in all. And now -I must say that if any 

 person will take the trouble of examining the perigyniums of these 

 plants, he will find there is neither a central wing nor central line on 

 their convex side ; but there is an opening on that side which extends 

 downwards to the very bottom of the beak, and in some instances to 

 the base of the perigynium itself. The curious nature of this opening 

 may perhaps have given rise to the various opinions as to its having a 

 wing or winged line. This opening may be seen by passing a knife 

 in a longitudinal direction along the outer or convex side of the beak, 

 which will be found to consist of two thin membranes, which overlap 

 each other, and thus form what a mechanic would call a spliced joint. 

 This is a description of a perigynium in its ordinary form ; but in some 

 we find one or both of these membranes that is not laid close down, 

 and thus may have given rise to the supposed central wing; in others 

 we find these membranes turned inwards, and in that state may have 

 o-iven rise to the supposed central line. When the beak is opened 

 out and laid flat, it will be found that what was the inner or concave 

 side is very thin in the middle, particularly so towards the point, and 



