ISO 3/r. Bkown on some remarkable Deviations 



become visible unless the seed be placed in a situation favourable 

 to germination, that very different directions may be given to its 

 radicular extremity, according to circumstances which we have it 

 ia our power to regulate. 



There is a fourth kind of anomaly in the structure of certain 

 seeds, which, as I have formerly described it*, I shall here notice 

 in few words. It is that which takes place in certain Aroidece, 

 especially in some species of Calladium. In these, the nucleus of 

 the seed is not properly a monocotyledonous embryo, but has an 

 appearance and economy more nearly resembling those of the 

 tuber of a root; for, instead of being distinguishable into a coty- 

 ledon, a plumula and radicula, and of germinating in a determi- 

 nate manner and from a single point, it is composed of a mass 

 whose internal structure is uniform, and on the surface of which 

 frequently more than one germinating point is observable. 



None of these anomalies appear to me materially to lessen the 

 importance of the characters derived from the seeds of plants ; 

 but they evidently render a minute attention to every circum- 

 stance absolutely necessary in all attempts either to deduce affini- 

 ties or establish genera from this source ; and they especially de-r 

 nionstrate the necessity of carefully ascertaining the state of the 

 unimpregnated ovarium; for, while its structure remains unknown, 

 that of the ripe fruit can never be thoroughly understood. 



« Prodr. Flor. Nov. HoU. p. 335. 



EXPLA. 



