Chapter 2

Our information concerning eggs essentially duplicates that already reported (see Stebbins, 1951). All egg clusters that we found were in small chambers within decomposing fir logs. In each instance the eggs were suspended from the roofs of the chambers. The clutch of six eggs was a compact mass, and the individual suspensory cables of the eggs were intertwined and fused with one another. The clutches of four eggs, although they too were compact clusters, had each suspensory pedicel distinct from the others. The surface of the eggs was lightly moist, but did not glisten with water, and each egg was completely free of the others. The outer coat of jelly of the fresh eggs measured about 6.4 by 5.7 mm. as they hung suspended; sizes were uniform and no egg was notably smaller or larger than the others.

We attempted to keep eggs artificially, but mold destroyed them after 12 days. We had difficulty keeping them wet without inundating them, for the climate at Las Cruces, New Mexico, where we kept the eggs, is exceedingly dry in summer. Until death, embryos were active and responsive to disturbances around them. This was at a time when the limb buds could not be detected and when the external gills were evident only under close scrutiny.

Two times we found adult female salamanders in the chambers with the egg clusters. The other two egg clutches seemingly had no attendant adult, but our method of going through a log was such that we could easily have alarmed any attendant animal well before we found the eggs, allowing time for the adult to move away from the eggs. We presume that incubation, so-called, in _A. hardii_ is similar to that found in other plethodontids (see, for example, Gordon, 1952:683). Our findings on the conditions of the stomachs of these attendant adults have been outlined above ("Food and Foraging"). Our limited data suggest that only females are found in chambers with eggs.

Summary

The montane relict plethodontid _Aneides hardii_ was studied in the field and laboratory in 1956-1958. Food items detected in a small sample of stomachs are listed tabularly. Two roundworms were found to parasitize the guts of the salamanders; the parasitism looks to be benign. Subterranean winter inactivity is thought to be an integral part of the salamanders' lives, and is suggested in part by the life cycles of the worms. Summer activity appears to occur at the ground surface in logs and talus, and underground; the latter site is suggested by certain ratios obtained in the samples, showing adults to outnumber young and males to outnumber females. The season for egg deposition seems to be in July and August. Clutch-size is lower than for any other plethodontid on record. "Incubation" of eggs apparently parallels that characteristic of other plethodontids.

Literature Cited

Bishop, S. C. 1947. Handbook of salamanders. Ithaca, Comstock. xiv + 555 pp.

Gordon, R. E. 1952. A contribution to the life history and ecology of the plethodontid salamander _Aneides aeneus_ (Cope and Packard). Amer. Midl. Nat., 47:666-701.

Lack, D. 1954. The natural regulation of animal numbers. Oxford, Clarendon, viii + 343 pp.

Lowe, C. H., Jr. 1950. The systematic status of the salamander _Plethodon hardii_, with a discussion of biogeographic problems in _Aneides_. Copeia, 1950(2):92-99.

Stebbins, R. C. 1951. Amphibians of western North America. Berkeley, Univ. Calif, xviii + 539 pp.

Szymanski, J. S. 1914. Eine Methode zur Untersuchung der Ruhe- und Aktivitätsperioden bei Tieren. Arch. ges. Physiol., 158:343-385.

Taylor, E. H. 1941. A new plethodont salamander from New Mexico. Proc. Biol. Soc. Wash., 54:77-79.

_Transmitted May 11, 1959._

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Transcriber's Notes:

Changed "vestigal" to "vestigial" on page 578: vestigal-winged flies.

Changed "inmature" to "immature" in Table 2: nematodes that were inmature.

Changed "auomatically" to "automatically" on page 582: not auomatically invalid.

Changed "Syzmanski" to "Szymanski" in Literature Cited on page 585.