IV.] BISERRULA, RICINUS, JATROPHA. 95 



to peep ; at the anterior end the seeds possess a small 

 lobe, or caruncle, which mimics the head or thorax of 

 the insect, and which even seems specially arranged 

 for this purpose ; at least it would seem from ex- 

 periments made at Kew that the carunculus exercises 

 no appreciable effect during germination. In Tri- 

 chosanthes anguina the long pods hang down, and 

 alike in size, form, colour and attitude closely resemble 

 snakes, as the specific name denotes. 



These resemblances might benefit the plant in one 

 of two ways. If it be an advantage to the plant 



Fig. 58.— Pod of Fig. sBo.— Seed of Fig. 58*.— Seed of 



Bisemtla. Castor Oil i,Ricinus). fairopha. 



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 the 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 



