. Natural science: a monthly review of scientific progress. that thisview is an error. Berkeleys observations were made upon thediseased roots of cucumbers nearly ten years before Greeffs dis-covery, and even four years before Schachts notice of the beet eel- p 2 ig6 NATURAL SCIENCE. March, worm. Not only does the English observer note the occurrence ofnematodes in root-excrescences for the first time, but gives twofigures in his paper, here reprinted by kind permission of the editorof the Gardeners Chronicle. One of them is an enlarged view of whatis now recognised as a female of Heterodera r
. Natural science: a monthly review of scientific progress. that thisview is an error. Berkeleys observations were made upon thediseased roots of cucumbers nearly ten years before Greeffs dis-covery, and even four years before Schachts notice of the beet eel- p 2 ig6 NATURAL SCIENCE. March, worm. Not only does the English observer note the occurrence ofnematodes in root-excrescences for the first time, but gives twofigures in his paper, here reprinted by kind permission of the editorof the Gardeners Chronicle. One of them is an enlarged view of whatis now recognised as a female of Heterodera radicicola embedded inthe hypertrophied tissue of the root. Eggs and young larvae arefigured, and Berkeley mentions that these occur in free cyst-likebodies, which appear to be regular membranous sacs. The cyst, he says, was destitute of any evident organicstructure, was not affected by iodine and sulphuric acid, but showedsome appearance of giving way under caustic potash. It was clear,then, that it did not consist of cellulose, but might possibly be some. Fig. 2.—Cyst female Heterodera from root-galls of Fig. i, with eggs and young the Rev. M. J. Berkeleys paper in Gardeners Chronicle, April 7, 1855. modification of xylogen. It is not conceivable that such a cyst couldhave been deposited by the vibrio itself, and we must therefore con-sider it as due to the irritation caused by the presence of the eggs,and exactly analogous to the cysts produced by the larvae of thecestoid worms in animal structures. We are not aware rhat anythingof the kind has ever been observed before in vegetable parasites; for,though the tissues of vegetables are greatly altered by the presenceof the larvae, which produce galls, it does not appear that they ever giverise to a free cyst, as in the present case, differing altogether from thesurrounding tissues. It is obvious that although Berkeley looked upon the body of thefemale as a cyst, his careful attempts to ascertain its nature bychemi
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