NATURAL HISTORY SOCIETY OF GLASGOW. 221 



tion, lavished by bountiful nature on man with so little labour on 

 his part. The tubers of Central Africa are very long, and at their 

 lower extremity have a number of thick protuberances resembling 

 in size and shape the foot of an elephant (one of them hence called 

 Testudinaria eleplmntipes. Of these, specimens weighing from 50 

 to 80 lbs. were seen by Dr. Schweinfurth, and the substance of 

 these tubers, according to him, was mealy, somewhat granular, 

 and easily cooked, being of a looser texture than our tenderest 

 potatoes, and decidedly preferable to them in flavour. The tubers 

 of the " Nyitti," or Helmia bulbifera, are similar to those of the 

 potato, but occur in the axils of leaves. In Bongo, Cucumbers, 

 Gourds, and a plant with a succulent calyx (Hebiscus esculentus) 

 are abundant, so that though the people cultivate but few vege- 

 tables, they find a variety of substitutes in these succulent-leaved 

 and tuber-bearing plants which grow wild. It is a remarkable 

 peculiarity of the flora of this region that all the species which 

 are not essentially shrubby or arborescent strive for a perennial 

 existence, and, as evidence of this, it may be observed that the 

 roots and portions of the stem beneath the soil either 

 develop into bulbs and tubers, or exhibit a determination 

 to become woody. Annuals occupy a very insignificant place, 

 and all vegetation seems to be provided with a means of with- 

 standing the annual steppe-burning, and of preserving the germs 

 of life until the next period of vitality recurs. When their corn 

 provision is exhausted, or when there is a failure in the harvest, 

 the Bongo find a welcome resource in these tubers. They subsist 

 on them for days in succession, and find in them the staple of 

 their nourishment, whenever they go upon their marches in the 

 wilderness. Many of their bulbs and tubers are extremely bitter; 

 and it is not until they have been thoroughly steeped in boiling 

 water, or have had the pungent matter roasted out, that they can 

 be eaten. Amongst these bitter bulbs are two belonging to the 

 Cucurbitaceae which claim notice, which are abundant everywhere. 

 " Impregnated with like bitterness are the rape-like roots of the 

 Asclepias,th.e huge tubers of the Entada ivalbergii and Pachyrrhizas, 

 as well as the various kinds of Vernoniae and Flemingiae, which are 

 dug up from a foot below the surface of the soil." Notable among 

 these numerous tuber plants is the diminutive Drimia, which lifts 

 its pretty red blossoms about a couple of inches above the rocky 

 ground, and possesses a bulb which becomes edible after prolonged 



