Another species is the key-hole limpet (Fissurella), distinguished by having a slit or foramen in the apex of the shell. The shells of Fissurella are generally rougher than those of Patella, and as a rule they live in warmer seas. In the limpet we find a departure from the general form of both animal and shell, both being bilaterally symmetrical, that is, having both sides alike. In the mollusks which have been presented thus far, the body has been twisted in the form of a spiral, making one side different from the other and causing the organs of one side to become atrophied. In the limpets the organs are paired, as they are supposed to have been in the ancestors of the living mollusks.
The most peculiar of all the mollusks, so peculiar, indeed, that they constitute a separate order (Polyplacophora) are the Chitons, or coat-of-mail shells. The shell is made up of eight separate pieces or plates, each locking with the other, the whole supported by and buried in a coriaceous mantle which forms a margin all the way around. This must not be confounded with the true mantle of the animal, for it is only a part of the shell. It is beset with bristles, spines or hairs, which add much to the peculiar appearance of this mollusk.
The Chitons live for the most part on rocks at low water and are said to be nocturnal in habit, feeding only at night. Their movements are slow and they appear to be very sluggish in all their actions. When detached and taken from their rocky homes they have the provoking (to the collector) habit of rolling up and are sometimes very difficult to straighten out again. There are about two hundred and fifty living species, found in all parts of the world.
In the foregoing pages we have called attention to a few types of marine snails, and what has been written has hardly more than touched upon this vast field. There are thousands of different species even more interesting than those which have been mentioned. There are the beautiful ear shells, or Abalones, the little periwinkle, so largely used as an article of food in Europe, besides a host of others too numerous to mention. The brief notes and the figures on the plate will convince the reader, it is hoped, that these inhabitants of the deep are not only beautiful and worthy of our attention and study, but are also of much practical and economical use to man.
Frank Collins Baker.
THE LEMON.
In 1636 an English report on the affairs of the navy gravely remarked that “the use of lemon is a precious medicine and well tried. Take two or three spoonfuls each morning and fast after it two hours.” The value of the fruit for certain disorders of the system seems to have received an early recognition. This was especially true with regard to scurvy, which in earlier days caused widespread mortality among seafaring men. Hawkins, in 1593, made the statement that more than ten thousand men had succumbed to the malady within the limits of his naval experience. The Crusaders under Louis IX. were severely attacked by scurvy, owing to their abstinence from fresh meat during Lent, and the history of the disease shows that it is occasioned by a lack of fresh meat and fruits. The efficacy of lemon juice was recognized by Drake, Davy, Cavendish, Dampier and many others years ago, and time has but added to the value of the fruit, while it has made it accessible to everyone. While Pomona is generally credited with having devoted her entire attention to the cultivation of the apple, it is stated on authority of an old Greek myth, that she gave considerable thought to the development of the Lemon and the orange. It appears that Pomona inclined not her ear to the supplications of her many admirers until Vertumnus, discerning her vulnerable point, presented the fair gardener with a grafting, which, under her skillful cultivation, developed into a lemon tree, and, as a reward, the favor of the wood-nymph was bestowed upon the youth.
Whether or not such was the origin of the Lemon, the fact remains that the fruit is most useful and the tree exceedingly attractive. Originally a native of Asia, it has become widely distributed in Europe, Africa and America, and although far more susceptible to injury from frosts than the orange, the trees are successfully cultivated under many conditions. Doubtless the best results in this country have been obtained in California. Thousands of acres around San Diego are planted with lemon trees while large districts in the Ojai Valley, Ventura, Santa Barbara, Pomona and Los Angeles counties are devoted to its cultivation. The tree is remarkable for beauty, and while it seldom attains large proportions, its pale green leaves, loosely-hanging branches, showy and fragrant flowers, together with the fruit that is found in all stages of development, produce a pleasing and highly ornamental effect. While the best crop of Lemons is generally gathered between December and April, the fruit should be picked every month for ten months of the year, in order to retain the best results. As a rule, the trees yield from one hundred and twenty-five to one hundred and forty boxes of the fruit to the acre, about the sixth year, but this number is increased to four hundred boxes when the groves reach an age of ten years.
The varieties of Lemons are distinguished chiefly by their size and form, and may be roughly classified as egg-shaped with blunt nipples and oblong lemons with large nipples. The sweet lemon and thin-rind Poncine and Naples belong to the first class, while the second includes such forms as the imperial, the Gaëta and the wax. The principal varieties grown in California are the Lisbon, Eureka and the Villa-Franca. Of these, the Eureka originated in California, while the Villa-Franca was imported from Europe. Besides the grateful quality of the juice, the expressed oil of the rind is used in the arts and has an intense odor of lemon, and the Pundits of Benares, quote a Sanskrit work, written about 1354, in which the oil is described as a valuable medicine. The acid pulp of the Lemon, after rasping off the rind, is pressed for citric acid, while the ottos of the Lemon, orange and bergamot, the preparation of which forms the chief industry of Sicily, are leading ingredients in the preparation of “Lisbon Water” and “Eau de Portugal.”
—Charles S. Raddin.