ster; the average
is 4.2 eggs if our clutch of one is discarded on the grounds it was
incomplete.

For comparison we have listed (Table 6) clutch-sizes for some other
plethodontids. It should be noted that these numbers refer only to eggs
deposited in clusters, and not to large ovarian eggs. Thus, _Aneides
hardii_ has the lowest range in clutch-size of any North American
plethodontid on record. It has been noted in other species that low
clutch-size is correlated with low productivity, slow population
turnover, and long average life-expectancy (Lack, 1954:103-105; Pitelka
and Johnston, MS). If this is the case with this salamander, several
other features in its environment and habits would tend to reinforce
such population structure: the animals are exceedingly well-concealed
(they were first described only 17 years ago [Taylor, 1941]), apparently
have few natural enemies (one garter snake [_Thamnophis_] was collected
within the habitat of the salamander in three years), apparently have
few and benign parasites, and abundant and readily available food.

Table 6.--Ranges and Mean Values of Clutch-sizes in Salamanders of
the North American Plethodontidae[1]

==========================================
| Range | Mean
---------------------------+-------+------
_Desmognathus_ spp.[2] | 11-40 | 20
_Leurognathus marmorata_ | 28 |
_Plethodon cinereus_ | 3-13 | 9
_Plethodon_ spp. | 8-18 | 13
_Ensatina eschscholtzii_ | 12-14 | 13
_Hemidactylium scutatum_ | 30 |
_Batrachoseps_ spp. | 7-74 |
_Aneides hardii_[3] | 1-6 | 3.6
_Aneides_ spp. | 7-19 | 13
_Stereochilus marginatus_ | | 57
_Pseudotriton ruber_ | 72 |
_Manculus quadridigitatus_ | 3-48 |
---------------------------+-------+------

[1] From Bishop (1947) and Stebbins (1951).

[2] Clusters of one and two occasionally found in _D. ochrophaeus_.

[3] This study, and from Lowe (1950).

_Eggs and "incubation"_

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 clu