. Zoology for high schools and colleges. Zoology. 480 Fig. 43B.—Siredon or larval Salamander.—From ' Tenney's Zoology. the adult, terrestrial form, sometimes being about a third of a metre (12 inches) in length, the adult being twenty centim- etres (8 inches) long, forming an example of what occurs in the Amphibians and also certain insects, of the excess in size and bulk of the larva over the more condensed adult form. This law is also strikingly observed in the Pseudes (Pig. 437). This fact of prematuritive, accelerated, vegetatire development of the larva over the adult is an epit
. Zoology for high schools and colleges. Zoology. 480 Fig. 43B.—Siredon or larval Salamander.—From ' Tenney's Zoology. the adult, terrestrial form, sometimes being about a third of a metre (12 inches) in length, the adult being twenty centim- etres (8 inches) long, forming an example of what occurs in the Amphibians and also certain insects, of the excess in size and bulk of the larva over the more condensed adult form. This law is also strikingly observed in the Pseudes (Pig. 437). This fact of prematuritive, accelerated, vegetatire development of the larva over the adult is an epitome of what has happened in the life of this and other classes of animals. The fossil, earliest representatives of the Amphibians, as we shall see farther on, were enormous, mon- strous, larval, prem- ature forms com- pared with their de- scendants. The same law holds good in certain groups of Crustacea (trilobites), insectSj fishes, reptiles and mammals. The axolotl or siredon abounds in the lakes of the Rocky Mountain plateau from Montana to Mexico, from an altitude of 4000 to 8000 or 9000 feet; the Mexican axolotl being of a different species, though closely allied to that of Colorado, Utah and Wyoming. The Mexicans use the animal as food. Late in the summer the siredons at Como Lake, Wyoming, where we have observed them, transform in large numbers into the adult stage, leaving the water and hiding under sticks, etc., on land. Still larger numbers remain in the lake, and breed there, as I have received the eggs from Mr. William Carlin, of Como. Thousands of the fully-grown siredons are washed ashore in the spring when the ice melts. They do not appear at the surface of the lake until the last of June, and disappear out of sight early in September. The eggs are laid in masses, and are 2 millimetres in diameter. Mr. F. F. Hubbell has observed in Como Lake, July 23d, young siredons four to six centimetres (1^2| inches) in length, and September 3d specimens eight centimetres
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