CHAP, m.] PLANTING BULBS AND TUBERS. 39 



seeds in oxalic acid before sowing' them, is 

 efficacious in making them vegetate sooner, as 

 there is a speedier combination between the 

 carbon in the seeds, and the oxygen in the acid, 

 than can be effected by the ordinary agency of 

 the air in parting with its oxygen to them ; but 

 it should only be done when absolutely ne- 

 cessary, as what is gained by the more rapid 

 developement of the seed, is generally lost by 

 the weakness of the seedling. 



Planting bulbs and tubers bears considerable 

 analogy to sowing seeds. The bulb or tuber 

 may, indeed, be considered as only a seed of 

 larger growth, since it requires the combined 

 influence of air, warmth, and moisture to make 

 it vegetate ; and then it throws out a stem, 

 leaves, and roots like a seed. There is, how- 

 ever, one important difference between them : 

 the seed expends its accumulated stock of car- 

 bon in giving birth to the root, stem, and 

 leaves, after which it withers away and disap- 

 pears ; while the bulb or tuber continues to 

 exist during the whole summer life of the plant, 

 and appears to contain a reservoir of carbon, 

 which it only parts with slowly, and as circum- 

 stances may require ; depositing matter to form 

 a fresh accumulation when it has wasted away. 

 Thouoh bulbs and tubers have here been men- 

 tioned as almost synonymous, modern botanists 

 make several distinctions between them. The 

 tunicated bulbs, such as those of the hyacinth 

 and the onion, and the squamose bulbs, such 

 as those of the lily, they consider to be under- 

 ground buds; while tubers, such as those of 



