106 



HISTOLOGICAL BOTANY. 



points around each of which concentric layers are disposed ; 

 those with but one centre are known as Simple (Fig- 120.a), 

 and others with two or more central points Compound 

 Starch-grains (Fig, 120.b). 



Starch-grains vary in their sizes and shapes in different 

 plants : thus, those of the Jagataraimo are very large and 

 ovate (Fig. 120.a and b) ; those of the Satoimo are very 

 small and globular (Fig. I20.e); those of the Ingen and 

 Fujimame (Dolichos cultratus) (Fig. 120.c) are large and 

 elliptical; those of the Satsumaimo (Ipomcea Batatas) 

 (Fig. 120.f) are large and spherical ; those of the Nishikiso 

 (Euphorbia humifusa) (Fig. 120.d) are small and bone- 

 shaped ; and so on. 



_, f Simple Starch-grains. 



STAKCH-GRAINSi „ , a . , . ,, ... 



{ Compound Starch-grains. Fiq. 121. 



3. CRYSTALS. 



Most crystals consist 

 of calcium oxalate, but 

 a few of calcium carbo- 

 nate. 



Crystals of calcium 

 oxalate are either octa- 

 hedral as in the Shu- 

 kaido (Fig. I21.a), or 

 prismatic as in the 

 Hanashobu (Iris Icevi- 

 gata, var. Kcempferi) 

 (Fig. 12l.c), or acerose 

 as in the Suisen (Nar- 

 cissus Tazzeta, var. 

 chmensis) (Fig. 121.b). 



Pio. 121. — Crystal spf calcium exalate.. 

 a Cluster of octahedral crystals of the 

 Shukaido ; b acerose crystal of the Suisen 

 (Narcissus Tazzeta, var. chinensis ) ; c 

 prismatic crystal of the Hanashobu (Iris- 

 lavigata, var. Ktmipferi). 



