3^ The Irish Naturalist. March, 



fruit in the matter of wind dispersal as the somewhat 

 better developed pappus of the disc fruit is to itself for 

 the same purpose. The ray fruit is certainly larger than 

 the disc fruit, but since it contains a fairly large air cavit}^ 

 it is probably (]uite as buoyant, or, perhaps, more so ; and 

 its pappus is by no means so ill-developed as to be 

 functionally useless, at any rate in Cornish specimens. 



Delpino also compares the appearance of the disc fruits 

 with that of small coleoptera, and suggests that this mimesis 

 may be of great use to the fruits after they have been 

 scattered by the wind. This, however, to my mind is 

 rather an unnecessary incursion into the realms of speculative 

 teleology. 



REFERENCES. 



HuTH, E. — Ueber geokarpe, amphikarpe und heterokarpe Pflanzen. 

 Abh. Ver. Natnrwiss. Frankfurt a. Oder. viii. 1890, pp. 89-121. 



Delpino, F. — Eterocarpia ed eteromericarpia nelle Angiosperme. Mem. 

 R. Accad. d. Sc. d, Inst. d. Bologna. S. 3, t. iv, 189^, pp. 27-68. 



Paglia, E. — L'eterocarpia nel regno vegetale. 



Ann. Bat. Roma viii., 1910, pp. 175-190. 



Becker, H. — Ueber die Keimung verschiedenartiger Friichte und Samen 

 bei derselben Species. 

 Beih. z. Bot. Centralblatt. xxix. Abt. i. 191 3, pp. 21-143. 



EXPLANATION OF PLATE 3. 



Fig. I. Three of the golden-brown, wrinkled disc-fruits of Picris echioides. 

 X 2-75. 



2. Three of the whitish, hairy ray-fruits from the same flower-head. 



X 2-75. 



3. Transverse section of disc-fruit. X 30. 



4. Transverse section of ray-fruit, x 30. 



Royal College of Science, Dublin. 



