1881. 



0)1 Fruits and Seeds. 



C27 



The pod of Biserrula Pelecinus (Fig. 24 a) also has a striking 

 rescmblauco to a cruslied centipede ; while the seeds of Ahrus preca- 

 tortus, both in size and in their very striking color, mimic a small 

 beetle, Artemis circumusta. 



Mr. Moore has recently called attention to other cases of this kind. 

 Thus the seed of Marti/nia diandra much resembles a beetle with long 

 antenna) : several species of Lupins liave seeds much like spiders, and 

 those of Dimorjjhochlamys, a gourdlike plant, mimic a piece of dry 

 twig. In the Common Castor Oil plants (Fig. 24 h), though the 

 resemblance is not so close, still at first glance the seeds might readily 

 be taken for beetles or ticks. In many Euphorbiaceous plants, as 

 for instance in Jatmpha (Fig. 24 c), the resemblance is even more 

 striking. The seeds have a central line resembling the space between 

 the elytra, dividing and slightly diverging at the end, while between 

 them the end of the abdomen seems to peep ; at the anterior end the 

 seeds possess a small lobe, or caruncle, which mimics the head or 



Fjg. 24. 



• 



Pod of Biserrula. Seed of Castor Oil (^Ricinus). Seed of Jatropha. 



thorax of the insect, and which even seems specially arranged for this 

 purpose ; at least it would seem from eipcrimcnts made at Kew that 

 the carunculus exercises no appreciable efi'ect during germination. 



These resemblances might benefit the plant in one of two ways. 

 If it be an advantage to the plant that the seeds should be swallowed 

 by birds, their resemblance to insects might lead to this result. On 

 the other hand, if it be desirable to escape from graminivorous birds, 

 then the resemblance to insects would serve as a protection* We do 

 not, however, yet know enough about tho habits of these plants to 

 solve this question. 



Indeed, as we have gone on, many other questions will, I doubt not, 

 have occurred to you^ which we are not yet in a position to answer. 

 Seeds, for instance, differ almost infinitely in the sculpturing of their 

 surface. But I shall woefully have failed in my object to-night if you 

 go away with the impression that we know all alx)ut seeds. On the 

 contrary, there is not a fruit or a seed, even of one of our commonest 



Vol. IX. (No. 74.) 2 x 



