ma:n'ual or ageicultuke. 245 



present in milk. The legumin of the leguminous plants, e.g., 

 peas, beans, clovers, and the avenin of oats correspond with it. 



There are two great systems of plant classification — the arti- 

 ficial and the natural. The artificial, or Linn^ean, as it is called, 

 after its inventor, the Swedish savant Linnaeus, takes as the 

 standard of its class division the relative number and position of 

 stamens and pistils. The latter system, however, has ousted 

 the Linnsean from modern use. And, more scientifically, the 

 natural system bases its principle of division upon similarity of 

 internal structure, and composition, and modification of organs in 

 plant groups. 



All plants are primarily divided into flowering and flowerless. 

 Excepting a few of the more highly-developed individuals of the 

 latter class (ferns for example, as representing acrogenoua 

 stemmed plants), they are all cellular plants, reproducing through 

 the agency of minute germs or spores. Flowering plants are 

 further divided into " classes " — those, firstly, with exogenous, and 

 secondly, those with endogenous stems. As previously stated, the 

 possession of an exogenous stem is accompanied ^\i.th that of reticu- 

 lated leaf vernation, and the presence of two cotyledons in the seed. 



Classes are subdivided into "sub-classes," which are dis- 

 tinguished by the presence or absence and varying arrangement 

 of the enveloping organs, and the relative position of the essential 

 organs of the flower. Next come " orders," or " families," em- 

 bracing forms of a generally uniform structure, especially as 

 regards flower and fruit ; and then in the order of particularity 

 follow " genera," " sub-genera," " species," and " varieties." 



The limitation of what is strictly implied by the term '' species," 

 in the animal and vei^etable kingdoms alike, is still a vexed 

 question with naturalists. Generally speaking, however, the 

 term implies the resultant group, constituted by the issue of a 

 single parent stock, and which has the power of reproducing their 

 like and no other. The individuals of a species may vary in 

 some essential points of structure; but still the offspring has the 

 tendency of assuming a closer and closer resemblance to the 

 original stock, if not prevented by external agency. In the 

 plants of certain orders there occurs a remarkable tendency 

 towards abnormal development of structural parts. Tlants are 

 then said " to sport." The turnip, cabbage and kohl-rabi — the 

 sea colewort as well, which is found wild on certain parts of our 

 coast — are all varieties of, and descended from, closely allied 

 species; but their tendency towards " sporting" has been taken ad- 

 vantage of by man ; and by the artificial means of agriculture, 

 their abnormalities have been fostered to an extent rendering 

 them valuable to the farmer. In the turnip the extra develop- 

 ment, or hypertrophy, is seated in the root ; in the cabbage, in 

 the leaves; in the kohl-rabi, in the stem. Cultivation has so 



