SCIENCE or GARDE^'I^'G. 



require to be watered with great constancy, but discrimi- 

 nation; giving to each only just what it is seen to need. 

 They should be watered solely in mild weather during 

 winter, a.s wetness conduces to injury by frost. 



4. — Propagating ly Seeds. 



The most common way of procuring a great number of 

 plants of one kind^ is by sowing seed ; indeed, this is the 

 means which nature herself has provided, and,, of course, 

 it is the most simple and efficacious. 



Eveiy seed has a shell more or less hard, to protect it 

 from external injury, and at its base is furnished with 

 what is called the seed-pore, (popularly the c\//;.^ which 

 performs two important functions, viz., conveys the 

 nutrient pulp to the seed while in a young and green 

 state, and previous to its becoming ripe, and also is the 

 point from which the roots and stem of the yovrng plant 

 proceed after germinating. 



"Within the shell is the kernel, consisting of the embryo 

 plant, with its radicle or root, its gemlet or stem, and the 

 neck between these, which afterwards becomes the crown, 

 besides the seed-lobe or lobes, containing materials fur 

 nouriishing it in the first stage of growth. 



In order to excite the embryo into action, and induce 

 it to grow, four things ai'e indispensable — heat, water, air, 

 and darkness. 



The heat is requh-ed to soften the nutrient materials in 

 the lobes, but without water it would be more likely to 

 harden these. Pure water is more appropriate than water 

 containing humin or other rich materials, that which is 

 contained in the lobes being sufficiently rich. 



Freely circulating air is indispensable for supplying 

 oxygen gas, and carrying off carbonic acid gas. a process 

 the reverse of what takes place in leaves expo^red to sun- 

 light. For the same rea.son light is injurious, by carrying 

 off the oxygen gas requisite in this stage of growth. 



In solving any sort of seed, these four circumstances 

 must be carefully attended to. On account of the ab- 

 sence of heat, accordingly, seeds will not vegetate during 



