64 W. N. F. WOODLAND 
INTRODUCTORY. 
Durine the rainy seasons (July to October) of 1914 and 1918 
T made a large number of observations and experiments on the 
facts of caudal autotomy and regeneration in the common 
Indian Gecko, Hemidactylus flaviviridis’ (Ritppel), 
a very familiar and useful ‘ snapper-up of unconsidered | insect | 
trifles’ found on the walls of every bungalow in the United 
Provinces. In January 1915 I read a brief paper® on the 
subject at Madras on the occasion of the second meeting of 
the Indian Science Congress, but until the present year I have 
not had an opportunity of writing up a complete description 
of the results obtamed by me. 
The more conspicuous features of caudal autotomy and 
regeneration in Jacertila, such as e.g. the intravertebral 
position of the cleavage or autotomy plane, the substitution 
of a continuous cartilaginous tube for vertebral centra, of an 
epithelial tube (an extension of the epithelium liming the 
canalis centralis) for the spimal cord, the change in lepidosis, 
absence of segmentation and subdivision of the muscles in the 
regenerated tail, and other features, have of course been known 
for many years (vide e. g. Fraisse ® in 1885, Brindley * in 1895, 
and Tornier ° in 1897) ; on the other hand, judging from recent 
literature on the subject known to me, there still appears to be 
a certain amount of uncertainty respecting even some of the 
main facts. E.g. in Morgan’s ‘ Regeneration’ ® it is stated 
1 The H. coctaeiof the ‘ Fauna of British India’. At least two other 
species or genera of Geckos are common in Allahabad, but the facts 
described in this paper apply to all. 
2 Published in brief abstract in the official account of the Proceedings 
of the Congress issued by the Asiatic Society of Bengal, and in several 
Madras daily papers. 
3 Fraisse, P.. ‘Die Regeneration von Geweben und Organen bei den 
Wirbelthieren, besonders Amphibien und Reptilien ’, Cassel, 1885. 
4 Brindley, H. H., “Some Cases of Caudal Abnormality in Mabula 
carinata and other Lizards”’, ‘ Jour. Bombay Nat. Hist. Soc.’, vol. xi, 
1897-8, p. 680. 
> Tornier, G., ‘“ Uber experimentell erzeugte dreischwanzige Eidechsen 
und Doppelgliedmassen von Molchen”’, * Zool. Anzeig.’, Band xx, 1897, 
p- 356. 
6 * Regeneration ’, T. H. Morgan, 1901. 
