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The Berea Grit of Ohio. Edward Orton.
tions therefrom. E. W. Claypole. On the discovery of an Archemediform Tenestellid in the Upper Silurian rocks of
Ohio. E. W. Claypole. Life-history of the Buckeye Stem-borer (Sericoris instrutana Clem.) E. W. Claypole. Some needed reforms in the use of Botanical Terms. Charles E. Ridler, The excavation of the Grand cañon of the Colorado river. C, E, Dutton. On the cause of the arid climate of the far West. C. E. Dutton. Evolution and its place in Geology. Edward S. Edmunds. The evidence from the Drift of Ohio in regard to the origin of Lake Erie, E. W.
Claypole. A short study of the features of the region of Lower Great Lakes during the Great
River age; or notes on the origin of the Great Lakes of North America. J.
W. Spencer. On the inhabitants of N. E. Siberia, commonly called Chukchis and Namollo. W.
H. Dall. A lawgiver of the Stone age. Horatio Hale. Ilex cassina, the black drink of the Southern Indians. John G. Henderson. Was the antelope hunted by the Indians on the prairies of Illinois ? John G. Hen
derson. Agriculture and agricultural implements of the ancient inhabitants of the Mississippi
valley. John G. Henderson. Houses of the ancient inhabitants of the Mississippi valley. John G. Henderson. Comparative differences in the Iroquois group of dialects. Mrs. Erminnie A.
Albert B. Prescott.
domestica. Burt G. Wilder. Remarks on the classification and distribution of Producti. S. H. Trowbridge. The temperature of North German Traps at the time of their extrusion. H. Car
michael. Recent existence of sword-fish, shark and dolphin in the fresh-water pond near
Buffalo, N. Y. Wm. Zimmerman, Antiquity of Man in America. W. De Haas. Progress of Archäological Research. W. De Hlaas. The Mound Builders; an inquiry into their assumed southern origin. W. De Haas. Additional facts on the fertilization of Yucca. Thomas Meehan. On the interpretation of Pictographs by the application of gesture-signs. W. J.
Hoffman. An alleged abnormal peculiarity in the history of Argynnis myrina. W. H.
Edwards. On a convenient form of slide case. Robt. Brown, Jr. On some relations of Birds and Insects. S. A. Forbes. Comparison of Maya dates with those of the Christian era. Cyrus Thomas. Notice of a Fern indigenous to Calisornia, but heretofore considered as an intro
duced bothouse species. Mrs. Leander Stone. Fossil teeth of Mammals from the Drift of Illinois. Wm. McAdams. The Unification of geological nomenclature. Richard Owen.
MIDDLESEX INSTITUTE, Malden, Mass., June 17.-The annual field meeting of the institute was held on Bear hill, in the Middlesex Fells, Stoneham. A large number of guests were present, and the day passed enjoyably. Many plants not previously collected were added to the list of our county flora, and Mrs. P. D. Richards found that rare plant, Habenaria hookeri.
June 22.-An exhibition of native plants from Malden, Medford and other parts of the county, was held in Institute Hall, and attracted a large number of visitors.
July 27.-A special exhibition of the native ferns of Middlesex county was given with gratifying success. Mr. Frohock exhibited Woodwardia angustifolia from Medford, Mass., found for the first time within the limits of Middlesex county, and Mr. Dame exhibited Botrychium matricariafolium from Stoneham.
Arrangements are partially completed for a course of scientific lectures to be delivered during the winter months.
QUARTERLY JOURNAL OF MICROSCOPICAL SCIENCE, July.-On the lymphatic system of the skin and mucous membranes, by E. Klein. The development of the water glands in the leaf of Saxifraga crustata, by W. Gardiner. The development of the Spermatozoa, Part 11. Helix and Rana, by J. E. Blomfield. On the early development of the anterior part of the wolffian duct and body in the chick, together with some remarks on the excretory system of the Vertebrata, by Adam Sedgwick. Observations on the cranial nerves of Scyllium, by A. Milnes Marshall. On the occurrence of corpuscles in the red vascular fluid of Chætopods, by J. E. Blomfield. Pacinian corpuscles in the pancreas and mesenteric glands of the cat, by V. Harris. Limulus an Arachnid, by E. R. Lankester.
THE GEOLOGICAL MAGAZINE, August.—On the Aichæan rocks, by C. Callaway. The Megaceros in Ireland, by W. Williams. The glaciation of the Shetlands, by B. N. Peach and J. Horne.
ANNALES DES SCIENCES NATURELLES, June.-Monograph of the birds of the family Megapodiidæ, by E. Oustalet, 2d part. New researches on the organization and development of Gordiacea, by M. Villot. Description of macrurous Crustacea from great depths of the seas of the Antilles, by A. Milne Edwards.
JENAISCHE ZEITSCHRIFT FUR NATURWISSENSCHAFT, July 31.On the muscles of the eye of Ganoids, by H. Schneider. The mouth-arms of Rhizostomæ and their appended organs, by 0. Hamann. The development of the middle germ-layer of vertebrates, by O. Hertwig.
VOL. xv. — NOVEMBER, 1881. — No. II.
ON THE MICROSCOPIC AND GENERAL CHARACTERS OF THE PEACH TREE AFFECTED
WITH THE “YELLOWS.”
BY W. K. HIGLEY.
SYMPTOMS OF THE YELLOWS. 1. Premature Ripening.—This symptom is one of the most common, although it is not by any means always noticed. In many cases it is very marked. During my investigation I have corresponded freely with persons upon this subject, and many have stated that this is only a marked symptom in certain varieties, prominent among which is “Stanlie's late.” Mr. John Williams, of South Haven, sent me specimens of this variety that ripened three weeks before the proper time. This symptom is not wholly confined to the peach affected with the yellows, as it is also sai to be produced by the borer and curculio, but from all the evidence that I have been able to glean, I think that it can be safely stated that it is an infallible symptom when noticed in some localities. I cannot agree with those who state that this symptom is only noticed in certain varieties, but think that although it may not always happen, yet when it does it is just as liable to be on one variety as another. It is, at all events, a thing to be looked after when the presence of this disease is feared.
2. Color of the Peach.— I have noticed particularly that affected peaches, when opened, presented a very abnormal appearance as to the position, extent and size of the pigment spots. In the normal fruit bright red spots are often present near the pit and, perhaps, even toward the outer portions of the cellular part,
while in the diseased fruit, especially that which has prematurely ripened, near the pit considerable red coloring matter may be noticed, often in a conglomerate mass, and scattered through the remainder of the fleshy portions, many oblong or rounded masses of the same color. Under the microscope these appear to be simply cells filled with a coloring matter that may be removed by treating with strong potassic hydrate, acetic acid, or alcohol. The skin of the peach also shows a highly abnormal color, generally simply spotted with red, but in some specimens that I have had the opportunity of examining, this red color assumed an oblong shape, the spots being arranged in bands. This symptom seems to be of the highest importance, as there is no other disease, so far as I am able to ascertain, that will produce the above results.
3. Production of Abnormal Branches.-Perhaps one of the most marked symptoms of the yellows is the abnormal production of branches, or rather branchlets. But the poinologist must guard against one important fact in diagnosing the yellows from this symptom, viz., the production of numerous twigs. Non-cultivation of any domesticated tree will often cause a great abundance of small twigs or shoots to grow from the secondary branches; they may continue as high as the sixth division into branches. Again a great proficiency of twigs may be produced by the use of much rich manure year after year. However, to return to the discussion of branchlets as an indication of the yellows, let it be remembered that it is the branchlets and not the twigs that are of importance. These are produced on the main or larger branches from lateral buds, and in some cases even from the trunk of the tree. They are slender wire-like shoots, often no larger than a needle, from two to eight inches long, and not seldom showing a tendency to throw out lateral or secondary shoots. They may attain to a much greater length, but, as far as I can ascertain, the above measurements form a good average. This peculiar feature of the disease is easily explained. A spore of the fungus salling upon some part of the branch, finds the conditions favorable for development and sends out its mycelium which ramifies through the tissues of the limb and soon fills up the passages, crowding the vessels and cells so that the flow of sap to the parts beyond this point is nearly stopped; thus the ends of the growing branches being choked, the sap is caused to flow to the lateral buds, and these having so plentiful a supply of nutriment, grow rapidly and throw out these wire-like shoots. This symptom, with the one previous, are sure and infallible guides to the detection of the yellows; they often occur together, but more often the former is the second stage, only appearing after the latter has been present the year previous. I examined carefully several specimens of these branchlets, and in two-thirds of them I found the mycelium of a fungus in the tissue. Those in which the fungus was present were from South Haven, the remainder from other localities showed no signs of mycelial growth. It is very probable, however, had time permitted extended sectional examinations, that I should have found, even in these, evidences of parasitical forms.
4. Microscopical Symptoms.—There are many marked peculiarities noticed when sections of the different parts of a tree are studied, but whether or not some of these will be produced by other causes than the yellows, is a subject too patent to need any discussion. One of the most important points noticed in microscopical examination, is the loose character of the cells and other parts of the section, both transverse and longitudinal. This would only be noticed by one who has carefully compared both sections of the healthy and unhealthy tree. I was very much surprised when I first noticed this condition of things, and hoping that it might give me some clue to the cause of the disease, I examined several more specimens, but with no important results, except that it was a constant character of the diseased specimens that I had; it appeared in sections of the root as well as in those of the aërial portions. Attention may be called also to the sheets of mycelia that are sometimes found between the layers of wood as probably another symptom. Some of the many investigators who attribute the yellows to a fungoid growth, consider this as very marked evidence of the yellows, but it is not near so marked as is the abnormal coloring matter noticed in the pith. In the specimens of the wood of diseased trees that I have been permitted to examine, the most prominent microscopical symptom was the decided separation of the annual growths of wood; in the space thus formed no structure was visible, although apparently filled with some material, perhaps the ends of mycelia. I found it quite difficult to make sections of the diseased limbs and other parts of the aërial portions of diseased trees, for, on account of this loose structure, the cells, especially of the bark, were