120 OBJECT LESSONS IN BOTANY. 



tlie circles of petals common in other flowers. Hence we 

 have a class of Glume-plants and of Glumeless-plants, or, as 

 the botanists saj, Glumifer^ and Petaliferje. Thus we 

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



1. AngiosjKrms I Exogens bearing stigmas and seed-vessels. 



2. Gymnosperms ; Exogens with no stigmas, and with naked 

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



3. Petaliferce j Endogens with no glumes and ordinary 

 flowers. 



4. GlumifercB ; 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 Dialypetalce, or Polypetalous Exogens, having flow- 

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

 Pose, Mustard. 



2. The Gamopetalce^ having flowers with the petals united 

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



3. The Ajpetalm^ having flowers without j^etals, eitlier 

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

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

 ger-root {Asarwn\ Poke {Phytolacca\ and Pig- weed {Ckeno- 

 podium). 



4. E'ext, the Gymnosperms are regarded as forming one 

 cohort, called the Conoids^ having the fruit usually in cones. 

 (Less. XXIIL) 



258. After tlie classes, wLat is tlie next step in analysis? How are the 

 Angiosperms subdivided ? Please define tlie Polypetalous Exogens ; the 

 Gamopetalous ; the Apetalous. What cohort 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 Glumiferous 

 Endoffens constitute ? 



