FOSSIL VA RÁ NID AE AND MEGALANIDAE. 
429 
due biological and phylogenetical study the distinctly Western — and 
even eventually Nearctic — o r i g i n of this latter named lizard, met 
with in Dalmatia and Croatia and eastwards, may be surmised. In examining 
such questions however, necessary importance must be attributed to the fact 
that in the course of their geographical distribution, the œcological charac¬ 
ters of different species of animals present important and even contradictory 
particularities . Bomb inat or pachypus for instance, in certain countries 
as Hungary, Austria and especially Switzerland, is to be found as a moun¬ 
tain or highland form, whilst in other regions, such as Northern Italy for 
example, in conformity with the m o u n t a i n 1 i z a r d (Lac. vivi¬ 
para Jacq.), it may be met with in the plains. 1 The same phenomenon is 
encountered with M. cristata Laur. and M. er. subsp. Kare Uni Strauch. 2 3 
What has been said will clearly show that the occurrence of s i n g 1 e forms 
must not serve as reason to justify any conclusion regarding the ori¬ 
gin of the fauna or other questions of general character. And though 
Prof. Tuzson’s proposition may be, according to Prof. Méhely, «very 
rigidly drawn up», the contrary could hardly be maintained of Prof. Mé- 
hely’s affirmation. In this case also, as in many others, the «juste milieu» 
will be the best way to choose. It is well known that forms exist which are 
tolerably indifferent to environment, and others- highly specialized, which 
partly originating from and partly having migrated to a certain faunistica! 
territory, present, in the biological sense, such a heterogeneous composite 
of the fauna that its distribution and migration cannot possibly 
always find a uniform explanation ; not counting the eventual autoch¬ 
thonal forms, the animal world of a fauna-territory may have gathered 
from the most different parts of the World, so that an absolute gene¬ 
ralization can never be applied. It is precisely biology, 
ßtoq itself, which, despite the steadfastness of its immensely far-reaching 
immutable laws, knows nothing of these rigid «rules» combined officially 
for upholding theories in a theoretical manner. Moreover, as regards the 
Western origin of Hungarian and European fauna, Prof. Méhely may again 
be referred to : I am alluding to his previous work upon the species of 
Spalax 3 in which he writes in 1909 (p. 241) absolutely contrarily to the 
quotations mentioned above (1912) as follows 4 : «t h a t is to say that 
1 Fejérváry, Über Ableph. pannon., Zool. Jahrb., Abt. f. Svit., Tìd. XXXIII, 
Jena, 1912, p. 571. 
2 Fejérváry, Zur herp. Fauna d. Rax- u. Schneeberggeb., Verb. Zool. Bot. Ges. 
Wien, Jahrg. 1917, p. 183. 
3 A földi kutyák fajai (Species generis Spalax), Budapest. 
4 Translated front the Hungarian. 
