92 
BULLETIN OF THE UNITED STATES FISH COMMISSION. 
along the shores (see plate XXVIII). Each camp is supplied with a diving suit and 
an air machine, which is mounted in a heavy barge-like boat, as shown in the illustra- 
tion (plate XXIX). This boat is daily rowed from camp to each place of operation. 
Arrived there, one man is diver, one tends his signal rope, one hoists and emijties his 
basket of shells, two turn the cranks of the air-pump, and two are at the oars to keep 
the boat well over him and carefully follow his wauderiug course upon the bottom in 
search of shells. Thus it requires several persons to operate each diving outfit, young 
boys being frequently employed as attendants. 
The diving suits, of which the Pearl-Shell Company keep about seventy on hand, 
are mostly imported from London. About thirty of them are kept in constant use 
during the season. They cost about $35 each. 
A fleet of five schooners, ranging from 20 to 150 tons, is employed in distributing 
the diving squads over the area beiug worked, supplying them with provisions and 
transporting their ever-accumulating heaps of shells to La Paz. A small steamer, 62 
feet long, has recently been added to the fleet. 
Two or three large warehouses at La Paz, containing the supplies and stores used 
in the pearl fishery, I observed, were well stocked with diving machinery, ship stores, 
aud jirovisious. In fact, there was about the establishment every appearance of a 
well-regulated and remunerative business. 
All equipments, provisions, etc., excejit the English diving suits, are bought regu- 
larly in San Francisco, Cal. 
In one of these warehouses at the time of my visit, were stored in sacks 80 tons of 
shells of the pearl-oyster {Meleagrina margaritifera). The principal revenue of the 
pearl fishery is derived from the shells, the bulk of which are shipped to Europe for 
manufacture into ornaments, knife-handles, buttons, and all those articles for which 
mother of pearl is employed. Although the fact is well known to most persons, it may 
not be out of place to state in this connection that pearl, or mother-of-pearl, as it is 
usually called, is but the nacreous interior of the shell of the pearl oyster, laid down 
in successive layers by the mantle of the animal, and that “pearls” are purely acci- 
dental growths, “ beiug caused by the deposition of nacre around some foreign object. 
This nucleus may be a bit of sand, a parasite, or some similar object, but it is said that 
usually it is an egg which has failed to develop properly.” This explanation might be 
further supplemented by the statement that the so-called pearl-oyster is not in any 
way like the edible oyster of commerce. 
Senor Hidalgo, manager of the La Paz pearl fishery, kindly opened his safe and 
exhibited the pearls representing the gatherings of the three preceding months, about 
$12,000 or $15,000 worth. 
They were separated into eight or nine grades, the lower grades constituting by 
far the greater number of those exhibited. Most of them were small and imperfect, 
aud of little value. The large, symmetrical, aud consequently valuable pearls of the 
lot, worth perhaps from $500 to $1,000 each, were only a dozen or so in number. One 
or two of these were black, or of metallic black hues, but I was informed that they 
were not less valuable than white ones of similar proportions, although not so readily 
marketable in America as in Europe. 
The largest of these pearls, as I remember them, did not exceed, perhaps, in size, 
the egg of the common blue bird (Sialia). It may be remarked that the largest pearl 
known is 2 inches in length, aud weighs 3 ounces. 
