INTRODUCTORY LESSONS. 



Vt 



5. Albuminous Seeds. Remove the shell-like coat of a castor bean, 

 and carefully split it flatwise. What at first seems to be a large plumule 

 proves to be free from the rest of the kernel, and with care you may be 



9. Seed of Willow or Dig- 

 ger Piue cut so as to show 

 the straight embryo in the 

 center of tho oily albumen, 

 a and &, embryo taken out, 

 the cotyledons (6) separated. 

 10- Seed of the Castor-bean, 

 a, the broad thin embryo 

 nearly dividing the albu- 

 men; &, the embryo removed 

 and the leaf-like cotyledons 



10 11 12 separated. 11. Seed of Da- 



tura (Brugmansiii), showing at a the bent embryo in the scanty albumen; 6, the embryo taken out and 

 the Blender cotyledons separated. 12. A grain of coffee, a, the straight embryo. 



able to get it out whole (Fig. 10.) It is a straight embryo with beautifully 

 veined, leaf-like cotyledons, embedded in a white, oily substance, which 

 makes up the mass of the kernel. This substance is called Albumen, a 

 name which applies to anything inclosed with the embrj'o by the seed 

 coats. Peas, beans, acorns, nuts, and most large seeds have no albumen. 

 Carefully cut thin slices from a well soaked coffee grain until its embryo 

 appears as represented in Fig. 12. The horny, folded albumen makes 

 up most of the seed. A similar, but smaller embryo, may be found in 

 the brain-shaped, fleshy albumen of the ivy seed. The embryo of the 

 Tree-Datura, or Stramonium, is shown in Fig. 11. 

 It has slender cotyledons, folded down against a 

 thick radicle, the whole embedded in tough, fleshy 

 albumen. Take the embryo of a Morning-Glory 

 seed and pick the bits of transparent, jelly-like 

 albumen out of the pockets in the crumpled coty- 

 ledons. An attempt to flatten out the cotyledons 

 will probably result in something like 6, Fig. 13, 

 which may lead you to suppose that the coty- 

 ledons are separately crumpled, which is not the 

 case. They stick closely together by their inner 

 faces, as do the cotyledons of other seeds you have 

 examined, and they are crumpled as one; but, being 

 notched at the end, they readily split down the 

 center. Buckwheat seeds will give you some trouble. 



13. Morning - Glory 

 Just appearing above the 

 ground with the seed coat 

 sticking to the cotyle- 

 dons, a, the swollen 

 seed; 6, embryo, with 

 the crumpled cotyle- 

 dons split down the 

 middle in the attempt 

 to flatten them. 



Indeed, it will 



