120 OBJECT LESSONS IN BOTANY. 



the circles of petals common in other flowers. Hence we 

 have a class of Glume-plants and of Glumel ess-plants, or, as 

 the botanists say, Glumifer^ and Petalifer^. Tims we 

 divide all the Flowering Plants into four Classes, viz.: 



1. Angiosperms ; Exogens bearing stigmas and seed-vessels. 



2. Gymnospevms / Exogens with no stigmas, and with naked 

 seeds, as the Pines, Firs, Larches, Cedars, Cypresses,Yews, &c. 



3. PetalifercB j Endogens with no glumes and ordinary 

 flowers. 



4. GlwinifercB I Endogens with glumes instead of petals, as 

 the Grasses, Sedges, Grains. 



258. Again, each of these Classes are to be subdivided into 

 Cohorts, as follows : the Angiosperms are divided (not very 

 naturally) into three cohorts, viz. : 



1. The DialypetalcB^ or Polypetalous Exogens, having flow- 

 ers with the petals distinct and separate, as in the Buttercup, 

 Kose, Mustard. 



2. The GwmojpetalcB^ having flowers with the petals united 

 into one piece, as in the Phlox, Morning-glory, Foxglove. 



3. The Ajpetalce^ having flowers without petals, eitlier 

 naked, or with only one circle of floral envelopes (wliich must 

 then be considered as sepals, wdiatever be the color) ; as Gin- 

 ger-root (Asarwn), Poke {Phytolacca), and Pig-weed {fikeno- 

 podi'um). 



4. Next, the Gymnosperms are regarded as forming one 

 coliort, called the Conoids, having the fruit usually in cones. 

 (Less. XXIII.) 



258. After tlie classes, wL at is tlie next step in analysis? How are tlie 

 Angiosperms subdivided? Please define the Polypetalous Exogens; the 

 Gamopetalous ; the Apetalous. What coliort do the Gymnosperms form? 

 Why ? What two cohorts do the Petaliferous Endogens form ? Define the 

 fifth cohort. Define the sixth cohort. What cohort do the Glumiferona 

 Endogens constitute ? 



