XVI 



INTRODUCTORY LESSONS. 



resemble nets. Examine the leaves of Iris, Calla, or any that are grass- 

 like, and you will see why they are called Parallel-veined. 



33. Nelled-veined leaves grow on Exogenous stems. Parallel-veined leaves 

 grow on Endogenous stems. The former belong to plants which grow from 

 Dicotyledonous seeds; the latter to plants from Monocotyledonous seeds. 



34. Flowers. Get a bunch of Mustard flowers AVall-flowers, single 

 Stock, or Radish flowers will do as well. Pluck a single blossom and 

 note these facts: The most conspicuous part consists of four yellow 

 leaves; outside of these are four smaller greenish yellow leaves in pairs 

 not quite alike. The latter are Sepals, and together form the Calyx ; the 

 former are Petals, and together form the Corolla. Pull off the sepals, 

 observing that they alternate with the petals. Next remove the petals. 

 The broad part of each petal is called the blade, the narrow part, the claw 

 (corresponding to the petiole of an ordinary leaf). Inside of the petals 

 you find six yellow-headed bodies with white stems, two of which are 

 shorter than the remaining four. These are the Stamens. Their stems 

 are Filaments ; the yellow heads are Anthers, and the yellow powder which 

 they contain is Pollen. In the center of the flower is a club-shaped body 

 called the Pistil. This is the young seed-pod, and by splitting it open 

 you may see the minute Ovules, which are the beginnings of seed. The 

 part containing the ovules is the Ovary ; the naked upper end of the pis- 

 til is the Stigma, and the part connecting the stigma with the ovary is the 

 Style. The end of the stem 



upon which the parts of the 

 flower grow is the Receptacle, 

 and the stem is called a Pe- 

 duncle. Fig. 47 will assist 

 you in learning these names. 



35. A Complete Flower 

 must have calyx, corolla, 

 Btamensand pistils; but, since 

 the office of a flower is to pro- 

 duce seeds, and these grow 

 from ovules, which pollen has 

 reached by way of the stigma, 



,'4. t 11 **-u L 47. Magnified MnRtard flower with four of the stamens, 



It IO11OWS tliat three petals and throe sepals removed. 



