Reptiles. 



8037 



Dates of Appearance and Song of a few of our Migratory Birds near Pen- 

 zance— Chiffchaff (in song), March 22 ; Wheatear (seen), March 23 ; Sand Martins, 

 April 2; Blackcap (in song), April 11 ; Willow Wren (in song), April 12; White- 

 throat (in song), April 28; Sedge Warbler (in song), May 1; Cuckoo (in song), 

 April 26; Cuckoo (reputed), April 21. — Edward Hearle Rodd. 



Conclusion of the History of the Incubation of the Python. 

 By E. W. H. Holdsworth, Esq., F.L.S., Z.S., &c * 



The python and her doings in the Zoological Gardens have been 

 so much commented on by the daily and weekly papers, that there 

 appeared to me to be no occasion for sending you any further notice 

 on the subject. Opinions published in your pages lead me, how- 

 ever to believe that all the facts of the case cannot be known to the 

 whole of your correspondents. I will, therefore, shortly state what 

 has been observed in this matter of the python and her eggs, and offer 

 some reasons for believing the snake to have been really engaged in 

 " incubation," as that word is ordinarily understood. 



The eggs were deposited on the l*2th of January, and the python at 

 once devoted herself to their care, coiling herself in the most regular 

 manner around and over them, so that it was necessary to move the 

 snake's head on one side in order to obtain a fair view of any of the 

 eggs. On two occasions the python came off her eggs to alter their 

 position, but did not leave them, and resumed her place when the 

 rearrangement was made. The continued attention of the snake to 

 her charge soon gave rise to a suspicion that she was incubating; and 

 it became an interesting question whether or not, under the circum- 

 stances, there was any unusual development of heat. No satisfactory 

 result was obtained from the first experiments, in consequence of the 

 difficulty of using the only available thermometers. This objection, 

 however, was removed by Messrs. Negretti and Zambia, who kindly 

 undertook the manufacture of a suitable instrument, and soon turned 

 out the most sensitive thermometer they have ever constructed. The 

 following table shows the results of the experiments made with this 

 instrument ; and to exclude all possible error in using it, the thermo- 

 meter was on each occasion placed and read off either by Mr. Negretti 

 or his partner. The temperatures of both male and female snakes 

 were observed, and, from the first, great care was taken that both 

 reptiles should be kept as much as possible under the same external 



* Reprinted from the 4 Field' newspaper, but kindly communicated by the author. 



