Robert E. C. Stearns, APRIL 27, 1900,
Science, pages 655-657
The number of foreign molluscan species
in California has notably increased in the
past few years, and includes both terrestrial
and marine forms, detected by various collectors
in and around San Francisco bay.
With the single exception mentioned
below, the introduction of these exotic
forms has been purely accidental, simple
incidents in the usual course of business
traffic or commercial interchange.
First, among the land shells we find the
well known snail
Helix aspersa, a common
European species, largely used for food on
the continent and familiar to persons who
have patronized the restaurants of Paris.
This species was intentionally introduced
or 'planted,' in California over forty years
ago by Mr. A. Delmas, of San Jose, Santa
Clara county, who brought the stock firom
France and turned it out among the vineyards
on the west bank of the Guadalupe,
a small river that flows northerly through
Santa Clara Valley and empties into the
southerly end of San Francisco bay near
Alviso.
The soil where the snails were
placed is a rich sandy loam and the place
well shaded. When the summer heats
reach the maximum, the
Helices descend
into the ground several feet, hiding in the
cracks that form, as the ground dries, and
the gopher-holes also furnish cool retreats
and protection. The region above named
is one of exceeding fertility. It was settled
by a few French families. The introduction
of
H. aspersa by Mr. Delmas was made
for edible purposes, or in common parlance
'with an eye to the pot.' Mrs. Bush, of
the Normal School in San Jose, informs me
that the snails have thriven, and have extended
their territory from the starting
point on the west bank of the stream to
the easterly side, and have multiplied to
such an extent, that in some instances they
are troublesome in the gardens.
Mr. Delmas,
the elder, also planted
H. aspersa, in
San Francisco and Los Angeles. I have
never met with it in my collecting rambles
in San Francisco or the outskirts of that
city, nor heard of its having been detected
by any collector. This particular plant
was probably a failure, for a more unfavorable
region than that of San Francisco
forty years ago, with its cold sea winds,
fog, sand-dunes and shifting sands and
sparse ligneous scrubby vegetation it would
be hard to find. At the present day the
chances for success are altogether better,
for the greater area of the city is covered
by residences, with plats of grass, garden
patches and flower-beds which are frequently
watered and the general conditions
are more promising. It would doubtless
find a congenial environment in Golden
Gate Park; its occurrence there is only a
matter of time. I have learned recently
that some party in the westerly section of
the city propagates or did propagate
H.
aspersa. Mr. Fred L. Button, of Oakland,
has informed me that it occurs
1 in many of
the gardens and private grounds in that
place, and that one of his neighbors employed
a man half a day 'cleaning them
out of his garden.' Professor Keep, of
the Mills College, last summer collected 'a
fine living specimen' at Pacific Grove,
Monterey, which is more than fifty miles
south of the original Delmas plant on the
Guadalupe.
It is now common in East Side Park and
is also reported as occurring in Elysian
Park in Los Angeles. These are, no doubt,
the descendants of the stock planted by
Delmas so many years ago.
2
Mr. W. G. Binney, in his 'Terrestrial
Air-breathing Mollusks of North America
etc.' (Vol. V., July, 1878), reports
H.
aspersa, as found "In gardens in Charleston,
S. C., and vicinity, where it has existed for
fifty years; it has also been found
at New Orleans and Baton Rouge; Portland,
Maine; Nova Scotia; Santa Barbara,
Cal.; Hayti; Santiago, Chili; etc.;" and
Mr. Binney, if I am not mistaken, has
raised them in his grounds at Burlington,
N. J. As he says, "it evidently is a species
peculiarly adapted to colonization."
I have always doubted its occurrence at
Santa Barbara; it has never been confirmed
by any collector to my knowledge. It was,
in the first instance, credited to this place
on the testimony of a communication to the
Zoological Society of London, by Professor
Edward Forbes, in which were described
the shells collected in the course of surveying
voyages of Captain Kellett and Lieutenant
Wood of the Royal Navy, in the
ships
Herald and
Pandora. The locality
marks and labels were, unfortunately, badly
mixed, and confusion was the inevitable result —
Lower California species were credited
to the far north, and so on.
A recent careful inquiry made for me by
a friend utterly failed to obtain any data,
showing its existence at Santa Barbara
3 or
thereabout at any time.
From the foregoing it will be seen that
this species is fully established on both
coasts of the United States and it is likely
to extend its territorial domain in harmony
with the prevailing spirit of the times.
Living
Helix pomatia, a larger species, also
European, has been imported by a leading
grocery firm in San Francisco to supply its
patrons. This is the snail
par excellence of
Continental epicures and was propagated on
an extensive scale in the palmy days of
ancient Rome as a dainty for the patrician
palate on festal occasions; it is not unlikely
that sooner or later this species also will be
found in some congenial spot outside of the
grocery store and in course of time become
an inhabitant of California.
More than fifteen years ago a species of
slug,
Amalia Hewstoni, made its appearance
in the grass plots of San Francisco; it was
described by Dr. J. G. Cooper. It soon became
a nuisance; even a regularly ordained
clergyman spoke of it as 'a slimy brute';
however this may be, it has now 'expanded'
its territory so as to include Seattle in the
north and San Diego in the south. Dr.
Pilsbry says it may be identical with the
European
A. gagates; it is not a native Californian.
In addition to examples of
Helix
aspersa I have recently received specimens
of
Zonites (Vitrea) cellaria Müll. and
Zonites (Vitrea) draparnaldi Beck, and the
little bulimoid,
B. ventrosus Fer, all from
the lawns and flower-beds of Oakland, collected
by Henry Hemphill.
Of the above,
Z. cellaria has an almost
world-wide distribution through the instrumentality
of commerce. On the Atlantic
side from Quebec to Charleston, S. C.,
along the coast, inland (in greenhouses)
at Alleghany City, Pa., and Detroit, MIich.
Z. draparnaldi is found in the greenhouses
of Seattle according to Dr. Pilsbry and
has before been reported as occurring in
Oakland. The little bulimoid form detected
by Mr. Hemphill has not, to my
knowledge, been previously found anywhere
in North America. It is a continental
species. I do not find in the books, any intimation
of its occurrence in the British
Isles though its absence from territory so
comparatively near is remarkable. It has
been reported from Bermuda. The occurrence
of these European forms of
Zonites
and
Bulimus in the gardens of Oakland are
quite likely due to plant importations. A
single example of the little
Helicodiscus
lineatus Say, was noticed by me several
years ago, as having been collected in Oakland
by Mr. Hemphill. Binney
4 says of
this peculiar form, that it "inhabits all of
the Eastern, Central and Pacific Provinces,
having been found from Gaspé to Texas;
on the Rio Chama, New Mexico; in Idaho;
in Oakland, Cal." This is misleading, as
it has not been detected anywhere within
the Pacific province as defined by him outside
of Oakland, and only here in the single
instance above meintioned. Mr. Hemphill
has also collected
Cochlicopa lubrica
Müll. (=
Ferrussacia subeylindrica L.) on
Grizzly Peak back of the university grounds
at Berkeley. This form has heretofore been
reported from Oregon and Alaska, and presumably
belongs to the circumboreal fauna.
1My esteemed friend, the late Dr. Newcomb, who
lived in Oakland many years, may have planted some
in his garden as an experiment. He had at one time
on his grounds several living California forms of different
species.
2I have been told that the employees in the park
are of the opinion that it was incidentally introduced
with foreign plants. They are not aware of the Delmas
fact. Its presence in the park may, perhaps, be
due to both.
3Vide my paper ' On
Helix aspersa in California,'
in Annals of New York Acad. Sciences, May, 1881,
pp. 129-139.
4Manual of American Land Shells, Bull. U. S. N.
Mus. No. 28, 1885, p. 75.