516 
surpassed. What our impression of Sitka 
might have been had we had the use of a 
launch for dredging can only be inferred ; 
from the nature of the littoral fauna and 
from the pelagic forms it seems as though 
we might have found great richness at 
depths from five to twenty fathoms. 
Owing to our limited resources for col- 
lecting at Sitka, and to the desire to get 
back to Puget Sound in time for embryo- 
logical investigations, we decided to return 
to Port Townsend at the end of three weeks. 
Here we were met by an unforeseen diffi- 
culty. It was in the very midst of the 
tourist season, and in addition to the usual 
tourists many Christian Endeavorers had 
taken the opportunity to visit Alaska. The 
result was that the regular boats were over- 
crowded, and our only chance of getting 
away at the time desired was on some 
steamer coming north with miners and re- 
turning light. Such a chance was offered 
by the ‘ Mexico,’ an extra boat put on to 
meet the rush to the Klondike. The 
‘ Mexico’ arrived at Sitka August 3d, after 
leaving about 300 miners at Skaguay and 
Dyea, and, as anticipated, she was practi- 
cally empty for the return trip. 
The captain of the ‘ Mexico,’ who had lost 
time on the trip north, wanted to save time 
on the return trip, and decided to take the 
outside passage from Sitka, thereby saving 
sixteen hours on the usual time of the in- 
side passage. It was the intention at first 
to enter the inside passage north of Mary 
Island, but later it was decided to run down 
to Dixon Entrance before leaving the open 
Pacific. We reached the entrance about 
midnight, but a light fog had settled, and 
for some hours the pilot caused the vessel 
to beat around at half speed or else to lie 
quiet. The water was too deep to anchor, 
and the effect of the strong currents on the 
vessel’s course was not properly reckoned, 
for at four o’clock in the morning of August 
5th the order was given to go ahead at full 
SCIENCE. 
LN. S. Von. VI. No. 144. 
speed, and twenty minutes later the ‘Mexico’ 
crashed into West Devil Rock, a charted 
rock some distance (38-7 miles) out of the 
regular course. The hole made in the bot- 
tom of the vessel was beyond question of 
repair, and at 6.30 a.m.she sank out of 
sight in 500 feet of water. 
After eighteen or twentyjhours in the 
open boats the passengers were landed at 
the Indian village of New Metlahkatlah, 
where they were taken care of by the In- 
dians and their chief, Father Duncan, until 
the ‘Topeka’ called for them, two days 
later, and carried them hack to Puget Sound. 
Nothing was saved but the hand baggage; 
most of the instruments and all of our sci- 
entific material, reagents, notes, books and 
theses, representing not alone the summer’s 
work, but unfortunately also much work of 
the previous year, now lie at the bottom of 
Dixon Entrance. 
Without reagents and instruments and 
feeling more or less upset by the shock of 
the wreck, the entire party found it diffi- 
cult to settle down again for work. A few 
dredging trips, however, enabled Mr. Har- 
rington to renew his supply of Entoconcha, 
while turbellaria, molluscs and some ccelen- 
terates were found in full maturity. The 
party soon broke up, and the material col- 
lected at Port Townsend and Port Orchard 
alone represents the work of the expedition 
of 1897. Gary N. CALKINs. 
MIMICRY IN BUTTERFLIES OF THE GENUS 
HYPOLIMNAS AND ITS BEARING ON 
OLDER AND MORE RECENT THE- 
ORIES OF MIMICRY.* 
Tue theory of mimicry suggested by H. 
W. Bates, in 1862, explained the superficial 
resemblance of a rare to a common species 
in the same locality by supposing that the 
latter possessed some special means of de- 
fence (such as unpleasant taste, smell, etc.), 
* Abstract of a paper presented by HE. B. Poulton 
before the Section of Zoology of the American Asso- 
ciation for the Advancement of Science. 
