38 



trasted by M. Edwards with the summcr condition of the šame animal. 

 Mr. Cox adverted particvdarly to the more ieniaikal)!c phsenomena of 

 hibeination, which, lie stated, vvere now undergoing the investigation 

 of Dr. Marshall Hali, who was about to lay the resultof his experitnents 

 on this subject before the Royal Society. 



Mr. Cox then proceeded to recapitulate the practical remarks which 

 had resulted from his previons observations, and which in the present 

 abstract have been embodied with them. He aftervvards enlered 

 into the consideration of temi)erature, and dwelt purticidarly on 

 the importance of maintaining it at a sufficiently high degree in 

 all coUections of tropical animals. On tlie question as to the degree 

 vvhich might safely be regarded as vsufficient, he lemarked that if ana- 

 logies drawn from the vegetable kingdom could be depended on, 

 reference might be made to a temperature of from 50° to 90°, being 

 that of the noble Palm-house of Messrs. Loddiges, in which those 

 natives of tropical climates flourish admirably. But it is evident 

 from experience that 50° \vill be sufficient to keep tropical animals 

 alive in this climate, and a temperature of from 50° to 55° will pre- 

 serve them in health and activity. To induce them to breed with us, 

 that temperature will not be high enough, for an emasculatingettect, 

 as has been observed by Mr. Yarrell in the Peccary and other ani- 

 mals, is produced by a cold climate : the fevv instances in vvhich some 

 of the Felis tribe have been fruitful in this country, being only to be 

 regarded as exceptions. To develope the organs of reproduction in 

 plants, a higher degree of temperature than that suited for their mere 

 preservation is reąuired ; this rule may be eąually applicable to ani- 

 mals, and the temperature of repositories for those of tropical climates 

 should therefore probably be allowed to alternate bet\veen 55° and 70°, 

 Mr. Cox repeated his opinion that sufficient humidity should at the 

 šame time be provided. 



Mr. Cox concluded by stating that he had long been of opinion 

 that the best tęst for the proper statė of the atmospheie in a mena- 

 gerie is vegetation. If the ])lants of a tropical or vvarm latitude thrive, 

 he conceives that the temperature and statė of atmosphere (for it is 

 not temperature alone which we have to regard, but the other qualities 

 of the atmosphere also, moisture, elasticity, <S:c.) cannot be far removed 

 from those reąuired for animals of the šame latitudes. H e assumes 

 that a perfect Fivarium should include vvithin its area a conservatory 

 containing plants, natives of countries of a character similar to that 

 of the animals inclosed. No apprehension need, he thinks, be en- 

 tertained of plants contaminating the air to any injurious degree, 

 if proper ventilation vvere established, and abundance of fresh unre- 

 spired air were supplied : the contrary vvould in fact be frequently 

 the case during the day-time, the experiments of Friestley having 

 shovvn that the purity of air vitiated by the breathing of animals is 

 restored by the growth of living and healthy vegetables freely ex- 

 posed to the solav light. 



