1837.] Journal of a Trip to the Burenda Pass in 1836. 929 



" Scarabeeus scutellatus, thoracis cornu incurvo apice bifido, capitis recurvato 

 bifido. 



" Scarabaeo gedeone paulo minor ; capitis cornu recurvo apice bifido, absque 

 dente. Thorax niger, laevis, nitidus, cornu magno, porrecto, incurvo apice bifido. 

 Elytra laevia, brunnea : differt a Scarabseo gedeoae, cornubus minoribus absque 

 dente." 



These characters are so good, that a description of my specimen would be but 

 a repetition. 



The female is similar in colors, but has no horns on head or thorax. They 

 emit a squeaking noise when touched, which proceeds, as in many other species, 

 from rubbing the extremities of the body and the elytra together. 



These beetles differ considerably in size and in the development of the promi- 

 nent projection of the thorax, some having it large and well defined, while others 

 have scarcely any signs of it. And yet though they thus differ, they must still 

 be regarded as one and the same species, because all couple with the same females, 

 which also differ much in size. This difference arises from the various degrees 

 of nourishment which the larvae have procured, for those which obtain a plentiful 

 supply of food, will grow to a much larger size than those which have been stinted 

 in this respect. 



The many varieties of a species arise chiefly from such causes, as a scarcity of 

 food and prematurely becoming pupae, (which change many undergo on finding 

 their supplies exhausted.) 



The pupa also, may be placed in an unfavorable situation, and therefore will 

 not produce so fine a specimen as one which has been more fortunately placed. 

 The pupae of beetles, and perhaps, of most kinds of insects, which are buried in 

 the earth require a moderate degree of moisture to bring them to perfection, and 

 it may be said that even in this state, the animal receives nourishment. 



In proof of this, I took a number of the grubs or larvae and the pupae of the 

 present species, as well as of some other kinds, and placed them in a box of earth 

 similar to the soil in which they were found. Many of the larvae died from not 

 finding sufficient nourishment, while others which were in a more forward state, 

 became pupae, but these were always much smaller than those which had been 

 full fed. 



The beetles produced from these were consequently small and the development 

 of the horns very slight. The full-formed pupae which I had taken, were placed, 

 some in moist earth and some on the surface of it. Those which were buried and 

 received nourishment from the soil, produced fine healthy beetles, while on the 

 other hand those which were on the surface or only partially buried, produced 

 imperfect specimens, the wings being shrivelled up and never coming to maturity, 

 while again numbers of the pupae dried up and never produced anything. 



This circumstance satisfied me that nourishment was as necessary to the pupa, 

 as to the larva and imago, and although the two latter alone take food, yet mois- 

 ture and warmth are felt and imbibed by the pupa, and are as necessary to the 



