40 MORPHOLOGY OF SPECIES 



/^th — Spathulate. 



5 th to 9th — Trifoliate. 



loth — Bifoliate leaf, with small lateral leaflet. 



nth to 17th — Trifoliate leaves. 



1 8th to 20th — Bifoliate. 



2 1 St — Spathulate. 



22nd to 29th — Slightly spathulate. 



There were no spiny branches in the axils of any of these 

 leaves. 



No. 4. — Seedling, 4-0 cm. long, grown under same conditions 

 as No. T, and in same soil. 



ist — Two leaves opposite : one difoliate, the other spathulate. 



3rd and 4th — Spathulate, nearly opposite, but not quite on 

 same level. 



5th and 6th — Trifoliate, nearly opposite, not quite on same 

 level. Subsequent leaves arranged spirally. 



7th to 9th — Trifoliate. 



loth to 30th — Linear, gradually becoming normal, and termi- 

 nating in spines. 



Spiny axils were developed in the axils of all the leaves after 

 the 7th. 



No. 5. — Seedling grown under the same conditions as No. 4, 

 6*5 cm. long. 



ist pair of leaves, opposite, trifoliate. 



2nd pair, not quite opposite, trifoliate. 



3rd to 9th — Trifoliate. 



loth to 1 2th — Spathulate. 



13 th — Bifoliate. 



14th and 15 th — Trifoliate. 



1 6th — Bifoliate. 



17th to 32nd — Spathulate, gradually passing into the linear 

 form, with well developed spines. 



In the axils of all the leaves after the 5th were spiny branches. 



No. 6. — Seedling, i"5 cm. long, growing in humus soil, germi- 

 nated in autumn and collected in March of following year. Had 

 twenty leaves, all trifoliate. 



No. 7. — Grown under same conditions as No. 6. Had thirty 

 leaves, all trifoMate. 



