Kx^'sm } LIFE HISTORY OF THE KANGAROO RAT. 21 
Den 4. 
September 20. 191S. In Calliandra type. Stony or gravelly soil, red, nearly 
denuded of grass. 
Species stored. Crams. 
Prosopis velutina 190 
Mollugo vertieillata (pure) 90 
Anisolotus trispermus (mixed, but mostly of this genus) 50 
Solanum elaeagnifolium (12 fruits) 2 
Per cent. 
Mollugo vertieillata (inseparable) 50 
Bouteloua rothrockii 1 
Bouteloua aristidoides 10 
Lepidium lasiocarpum • Tr. 
Polygala puberula Tr. 
Ayenia mierophylla l— 2 
Portulaca suffrutescens 1 
Aplopappus gracilis - Tr. 
Alternantbera repens 1 
Tridens pulchella 1 
Plantago ignota 33 
Panicum hallii Tr. 
Fleshy fungi (puffballs) — 
41 M) 
Total T34 
Fifteen species represented in addition to the fleshy fungi. No perceptible 
grass growth from the summer rains here, therefore dependent on a wide variety 
of scattering plants. 
Den 0. 
October 17, 1918. Mixed type, partially denuded, no growth from summer 
rains. Sandy soil. 
Species stored. Grams. 
Bouteloua rothrockii (crowns) (heads 1 to 2 per cent) 1. 435 
Bouteloua rothrockii (heads and crowns, about 50 per cent of each) 325 
Bouteloua rothrockii (with small percentage of crowns) 315 
Boerhaavia wrightii (with a few grass crowns) 150 
Prosopis velutina 90 
Solanum elaeagnifolium (3 fruits) Tr. 
Total 2,315 
Four species represented. Count of 100 grams of stored Bouteloua crowns 
gives 1,700, or 17 crowns per gram. At this rate there were at least 27,000 
crowns stored in this burrow. If a density of 250 plants to the square yard be 
assumed la high estimate) these crowns represent the total B. rothrockii on 104 
square yards of range surface. Further examination of the vicinity of this den 
showed that the surrounding area was not completely cleared, but was devoid of 
B. rothrockii, while still having B. eriopoda with crowns undisturbed. 
Den 11. 
April 9, 3919. In partially denuded land where good spring growth of 
Esehscholtsia was in bloom at time of excavation. Stomach of spectahilis killed 
