1905. | AMPHIBIANS AND REPTILES. 201 
which lies at an altitude of about 7600 feet, was fruitless. Inthe 
month of September 1904, however, when we revisited this 
district, I was able to ascertain that these Newts live regularly in 
the stream below Contreras (altitude 8090 feet) down to about 
7900 feet, where the stream leaves the hills, and runs, still 
swiftly, in its stony bed through the Pedregal, or recent field of 
Java, then through rich evergreen meadows into Lake Xochimilco. 
Moreover, I can now add with certainty that A. altamirai is 
absolutely aquatic throughout its life. The natives (millers, field- 
labourers, and boys) knew the creatures well. They called them 
“axolotes sordos” (deaf, having no ears), and described them as 
axolotes sit aletas (without winglets, meaning gills); when I 
searched for them on land, on the bordering meadows, under 
stones, or amongst the trees, the people laughed at my ignorance 
of expecting to find “fishes” on dry land. ‘There are no fishes in 
that stream. But this, their “ fish,” they pronounced as no good, 
because these axolotes de cerro (Mountain Axolotl) are not eaten 
like the ‘ axolotes del lago.” 
During our last visit the mountain-streams were transformed 
into turbid roaring torrents, and it was only at a few spots that 
the Newts were visible, generally in some stiller water, in the 
shelter of some great boulder. There they stood, or rather were 
lying, on little patches of sandy bottom, the larvee working their 
gills vigorously, the adult motionless except for the undulating 
tail, and never rising to the surface to breathe. They were all 
extremely shy, quickly hiding beneath or between the stones. 
In the Montes de las Cruzes, close to the railway-station Dos 
Rios, the streams form here and there little swamps or ditches, 
with much watercress in the slowly-flowing water; there we 
found plenty of larve; the adult only in the running water. 
Not one of these mountain-streams runs dry. 
The lungs are well developed. 
The only specimen, a larya 100 mm. long, which I succeeded in 
bringing home alive in 1902, metamorphosed within 8 weeks, 
losing the fins and gills, and closing the gill-openings completely, 
but it died before losing the yellow and black piebald coloration. 
The distribution of Amblystoma in Mexico coincides absolutely 
with the large central and western portion of the country, which 
has been covered with volcanic masses, repeatedly or successively, 
since the Kocene epoch ; and the last outburst, which produced the 
Pedregal near Mexico, is known to have occurred after this part of 
the country was already inhabited by man. It was impossible for 
- Amphibia to live on such a terrain until it was weathered enough 
to sustain a permanent and moisture-loving vegetation. In fact 
every locality where A. tigrinwm is known to occur is on the 
Quaternary, mostly sandy, patches formed by the disintegrating 
debris of the voleanic masses; or it is found in the lakes, all of 
which are partially filled-up mountain valleys. 
We have to conclude that the Amblystomas are recent 
immigrants from the North. Where they have met such lakes, 
