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fly (Musca) and Eristalis, he finds under the hypodermis an extremely rich plexus of ganglionic cells, connected on one hand with the chief nerve-centers, and on the other with sensitive terminal nerve-branches.-In a paper read at the same meeting by M. Jourdain, on the sensorial cylinders of the internal antenna of crustaceans, he states that while these have undoubtedly the characters of an organ of sense, they cannot be those of smell.
-Mr. W. H. Ballou, in the Chicago Field, gives an account of the fisheries of eels in the Oswego river, New York, and a good account of the habits of the fish.—Mr. B.-B. Redding of the California Fish Commission, recently read an article on the propagation of fishes before the Academy of Sciences of that State. He dwelt especially on the enormous fertility of fishes as an indication that the sources of supply of human food were only beginning to be appreciated, and that the limit of human population as set down by the Malthusians is as remote as it ever was.
-- M. Bocourt of the Commission Scientifique de la Mexique, has recently investigated the structure of the scales of the Scincoid and other lizards with fish-like scales. He finds the former to be perforated by canals which divide the scales into numerous areas. The similar scales of Tretioscincus, Gymnophthalmus and allies from tropical America are homogeneous in structure.
NOTES ON THE GRAPE PHYLLOXERA AND ON LAWS TO PREVENT ITS INTRODUCTION.— I have received the following letter from a well-known grape grower of St. Louis, Mo., who is largely engaged in the exportation to France and other countries of American grape-vine cuttings, and as it touches a question of deep general, even international, interest, I will make it the text for brief coniment.
On page 3 of your American Entomologist, you urge the grape-growers of California not yet afflicted with Phylloxera to exercise the utmost vigilance to prevent the introduction into their own localities of infested vines or cuttings.' This last word, to me at least is unsatisfactory. Why should you support that erroneous prejudice? Is it not true that in winter, when cuttings are made and shipped, it is impossible to find a live Phylloxera on them, or any eggs of this insect ? The winter-egg, if it exists at all, does not exist on one year old wood, certainly not here nor in Southern France. Ask Aimé Champin; ask Leenhardt, Robin, Planchon, even; they all looked for it in vain just as you did yourself.
But while Spain, Italy, Hungary work to get the prohibition of the importation of cuttings repealed, as necessary to their salvation and free from any danger of importing the destructive insect, such a word from you may frustrate their endeavors.
ISIDOR BUSH." * This department is edited by Prof. C. V. Riley, Washington, D. C., to whom communications, books for notice, etc., should be sent.
The ravages of what has now come to be more generally called the Phylloxera, though the term should always be qualified, since there are many other species besides that which attacks the grapevine, have attracted so much attention in foreign countries and caused so much fear in those countries not yet invaded by it, that the most stringent laws have been enacted to prevent such invasion. Some of these laws are injurious and unnecessary in so far as they prohibit the importation of all living plants, and at Cape Town, more particularly, they have been carried out with such zeal, that a cargo of potatoes arriving from New Zealand was recently destroyed for fear that the pest might be imported therein. A great deal of controversy has grown out of this stringent legislation, and Dr. Maxime Cornu has lately submitted a report, in which, while confessing that Phylloxera vastatrix is confined to the grape-vine and can flourish on no other plant, he yet recommends the following of the example set by Algeria, wnich is to forbid the introduction of all vegetable products whatever except those absolutely required for consumption.
I have been too busily engaged during the last few years with other injurious insects to give very much attention to the grape Phylloxera in this country; yet I have made continuous observations which confirm all that I have in past years written on the subject, and from which I do not hesitate to declare that it is going beyond the bounds of reason to prohibit the importation of anything more than grape vines or grape cuttings from countries or districts where the grape Phylloxera is known to occur.
The life history of this interesting insect may be thus briefly stated: Starting from a stem-mother, it multiplies agamically through an indefinite number of generations, either in galls on the leaf or in cavities or on swellings on the roots. Its spread is naturally slow in the unwinged condition, whether on the surface or beneath the ground. But winged, agamic females are produced during the late sunimer and autumn months, and these are the true migrants of the species and disperse and spread from vineyard to vineyard through the atmosphere. They lay some half-dozen eggs only, in such situations as afford shade and moisture, and from these come the only true males and females, which are mouthless, feed not, and are born simply to procreate, the female laying, either below or above ground, a single, and the only directly impregnated egg, which has been termed the winter egg, and which in the spring following gives birth to the stem-mother which may either found a colony in a gall on the leaf, or upon the root—the latter being the more common habit.
The prohibition of other products than grape vines is based upon the supposed possibility of winged females settling thereon and depositing the few eggs which give birth to the true males and females, which last produce the “winter egg." Now the experiments which I made in 1875 (recorded in the Transaction of the St. Louis Academy of Science, October, 1875), and which were the first recorded of their kind, show that the eggs from the winged females are most often laid in or on the ground near the base of the vine, and that they are so delicate as to require specially favorable conditions of moisture and temperature to en: able them to hatch. I do not hesitate to express my conviction that when deposited on anything else than the lower, tomentose surface of the living leaf of the grape vine, where they can receive moisture by endosmosis, or in the crevices or irregularities of earth, that receives from dew or other sources a due amount of moisture, they will infallibly perish. But even supposing that these eggs could hatch, and the resulting female should lay the impregnated egg upon any other living plant, and that this egg should in due time give birth to the stem-mother, she would inevitably perish without issue for want of appropriate food; while to suppose that all these operations could go on upon any other product or substance than living plants, or upon the dry parts of plants, is to exhibit crass ignorance of the peculiar conditions necessary to the perpetuation of the species at these particular stages. With the utmost care in endeavoring to supply the natural conditions, I have failed nine times in ten to obtain the sexual individuals, and still more frequently to get the impreg. nated egg, and such has been the experience of others in Europe. The danger of introducing this insect upon anything else than the grape vine, where a voyage has to be made in the tropics, is yet more remote, as even supposing the “winter egg ” could be produced it would prematurely hatch on the voyage.
The only way, therefore, in which Phylloxera can be conveyed from one country to another widely separated therefrom, is upon grape vines, and here we come to the question raised by Mr. Bush. My recommendation to use certain resisting American vines as stocks on which to graft the more susceptible European vine has resulted in an immense traffic between this country and Europe in American cuttings, and nurserymen engaged in this business, however unbiased they may desire to be, naturally lean toward that side of the question which furthers their own interest. The insect may be carried on the roots of vines during the winter, either in the dormant larva state or in the “winter egg" state, and while later researches, here by myself and abroad by others, have confirmed my previous experience in this country, published five years ago, as to the rarity of the “winter egg" on the canes above ground, and the more recent observations would seem to indicate that wherever it is thus found above ground it is produced rather from the gall-inhabiting type than from the more dangerous root-inhabiting type, yet the fact that this "winter egg does occur upon almost any part of the plant above ground, and more particularly under the loose bark of the two-year-old cane, “winter egg
renders it quite possible that the insect ray be carried upon cuttings in this “ winter egg" state, and fully justifies the prohibition of the introduction of such, as well as of rooted plants, from any country where the insect is known to occur. Indeed, considering the rarity of shipment of rooted vines, I strongly believe that the insect was originally introduced into Europe from America in the
state upon cuttings. I would say, therefore, to those countries desirous of defending themselves from this scourge, that all danger is removed when vines and all parts of vines from infested countries are kept out. With such prohibition, all requirements are met and all legislation that goes beyond this must necessarily be hurtful to general industry; while the prohibition of traffic in American vines in countries where the grape Phylloxera is known to already occur can have no useful end and may be detrimental.
That the rarity with which the impregnated egg is found above ground greatly reduces the chances of Phylloxera introduction by cuttings is true, but in a country desiring protection from such a scourge, the remotest chance should not be risked. Mr. Bush is wrong in supposing that this egg may not occur on one year cane. I have found it upon such, and it may even occur upon the dried leaf where, in all probability, it is destined to perish.
While, therefore, I believe that the laws cannot be too stringent in preventing the introduction and use of grape vines in any living condition into a non-infected from an infected country, it is equally true that there is no danger in the mere passage through such a country of such vines or cuttings. These are necessarily boxed, and can only be safely and properly shipped during the cold or non-growing season, when the egg is dormant, so that there is a practical impossibility in the introduction of the insect by the mere passage, whether of vines or cuttings.-C. V. Riley.
CECROPIA CocooNS PUNCTURED BY THE HAIRY WOODPECKER.One of the most interesting as well as difficult problems in entomology, is the relation which the cocoon sustains to the pupa, and the various ways in which the cocoon offers protection to the pupa or future imago. In particular is this true of the Lepidoptera. That cocoons to an extent equalize rapid changes of temperature and prevent the loss of moisture by the pupa, is beyond a doubt. But that they offer protection against other natural destructive agencies, such as mice and birds, is, in the case of the latter, to a certain extent untrue. There is at least one bird, the. hairy woodpecker (Picus villosus Linn.), from whose beak the staunch cocoon of the Cecropia offer no protection whatever.
In the early part of the winter of 1879-80, I noticed one of these birds clinging to a twig, pecking away at the parchment-like covering of a cocoon attached thereto, in a manner that amused me very much, and I was hugely enjoying its (as I supposed) vain
attempts to penetrate it. But when it hopped to an adjoining limb, shook itself and performed in a manner which years of observation had taught me was not indicative of a hungry bird, I began to think its powers had been vastly underestimated. By the aid of a ladder the cocoon was obtained and found not only to have been punctured, but all the soft and liquid parts extracted. As there were others attached to the same tree which upon examination proved to be uninjured, I was led to believe the bird had found a weak part.
After a few days these were examined and another found to be punctured, this time fairly upon the crown and apparently in the strongest part. I now saw what had before escaped my notice, viz: that by the situation of the first cocoon it was accessible to the bird only from below, which accounted for the puncture being near its base, close to the twig. A short time afterward, on passing another tree, out from anong the branches flew the little murderer, and, as usual, a pánctured cocoon was found, the puncture yet wet with the juices of the pupa, showing that I had surprised the bird while at breakfast.
Afterward an examination of over twenty cocoons, found in a small grove of Negundo aceroides, showed only two uninjured.
That the birds were not in quest of parasites is at once evident, as a parasitized larva of one of these moths reaches only the first stages of the pupa state, as the many cocoons I have examined contained only the dried skins, in nearly all cases, of larvæ apparently having expired immediately after having constructed their cocoons, leaving at this season nothing containing any liquid matter whatever, and nothing to afford nourishment for birds.
A year has gone by, and at this date (January) the little destroyers are at work, and I can easily distinguish the dry rattling sound, the death knell of the beautiful moth, the larva of which seems to be as destructive to vegetation as the imago is innocent. So far as I have been able to observe, the birds do not attack these cocoons (a number of which accompany this paper) until winter, when other insect food is not so easily obtainable. In fact, this seems to be a source of subsistence stored up for this season of the year, always fresh and, to all appearances, at all times available.-F. M. Webster, Waterman, Ills.
NOTES ON THE ELM-TREE LEAF-BEETLE (GALERUCA XANTHOMELÆNA).- Perhaps the following may in part answer some of Dr. LeConte's inquiries about the imported elm leaf-beetle. My first acquaintance with the insect was in October, 1877. My friend, Mr. H. L. Otterson, a farmer, of Cream ridge, New Jersey, drew my attention to a strange foray of “squash bugs” (as he called them) in the garret. They swarmed in every hiding-place, seeming to take special delight in the old clothes and certain rolls of
This cocoon was opened nearly two months afterwards at the Bloomington meeting of the Illinois State Nat. Hist. Society, and the pupa found to be still alive.