AD TLORAM INDICAM (baLSAMINE^). 107 



mountains and Ceylon), that practically it is of little aid in 

 assisting either the student or the systematist. 



The caulescent group presents a number of inosculating sub- 

 divisions, of which we have adopted six, founded primarily on the 

 habit and foliation of the species. This has often obliged us to 

 separate plants that are very closely related indeed, and even more 

 often to refer species of more dubious affinity to one or other 

 group in an arbitrary manner. As it is, we have chosen what we 

 take to be the lesser evil, and only after vainly attempting to 

 group the species better by various combinations of the following 

 important structural peculiarities : — 



1. The seeds, which are numerous or few, with the testa polished, 

 granulate, reticulate, pustulate, or almost villous. These afford 

 excellent characters, but often not available in herbarium speci- 

 mens ; and similar seeds sometimes occur in plants of very different 

 habit and floral structure. 



2. The capsules, short, broadly elliptic, acute at both ends ; or 

 narrow, terete, or club-shaped, also afford excellent characters. 



3. The form of the two combined lateral petals (called by 

 Edgeworth and by us alee), which an inspection of the garden 

 Balsam, and of the Indian species in a living state, shows to be 

 extremely variable. In some these are long and pendulous, in 

 others they project horizontally and laterally ; the length of the 

 posticous lobes of each ala varies extremely, and even in the same 

 species (/. leptoceras and others), it may itself vary from almost 

 undivided to manifestly three-lobed. In I. tingens, Edgw., one lobe 

 is developed in aestivation within the spur. 



4. The anticous petal (vexillum, Edgw.) may be erect or pro- 

 jecting, flat or arched, entire or bilobed, keeled, cristate, or even 

 spurred down the mesial line of the back, the spur sometimes ter- 

 minating in a clavate gland (J. racemosa, Y&r. poli/cer as). Grreat 

 variation of this dorsal appendage in one species is exemplified by 

 many. 



5. The posticous or spurred sepal, called by us labellum (by 

 Edgeworth galea), undergoes very many modifications in the 

 genus, from a broad slightly concave lamina (J. scdbrida, tuber- 

 culata, &c.) to a funnel-shaped organ with a very long spur (J. 

 leptoceras and many others), a cornucopia (/. longicornu), a blunt 

 straight sac (Z. Walker cb, Jerdonice, &c.), or a sac with a longer or 

 shorter spur. This sepal is the most deceptive of all as affording " 

 characters : in I. longicornu it varies from a mere cone to a broad 

 deep sac with an abrupt spur ; in some of the section Oppositi- 



