Page:Popular Science Monthly Volume 58.djvu/576

568 from which nerves are given off to the eyes and other sense organs of the head. As illustrations from the monograph we have, in Fig. 2, reduced sketches of the drawings of the nervous system and the food canal in the adult silkworm. The sketch at the left hand illustrates the central nerve cord, and the small one near the center shows one ganglion enlarged, and part of the breathing tubes connected with it. The original drawing is on a much larger scale, and reducing it takes away some of its coarseness. All of his drawings lack the finish and detail of Swammerdam's work.

He showed also the food canal and the tubules connected with the intestine, which retain his name in the insect anatomy of to-day, under the designation of malpighian tubules. The silk-forming apparatus was also figured and described. These structures are represented, as Malpighi drew them, on the right of Fig. 2.

This monograph, which was originally published in Latin in 1669, has been several times republished. The best edition is that in French, dating from Montpellier, in 1878, and which is preceded by an account of the life and labors of Malpighi.

Anatomy of Plants. Malpighi's anatomy of plants constitutes one of his best as well as one of his most extensive works. In the folio edition of his works, 1675-79, the 'Anatome Plantarum' occupies not less than 152 pages and is illustrated by ninety-three plates of figures. It comprises the structure of bark, stem, roots, seeds, process of germination, treatise on galls, etc., etc.

The microscopic structure of plants is amply illustrated, and he anticipated to a certain degree the ideas on the cellular structure of plants. Burnett says of this work: "His observations appear to have been very accurate, and not only did he maintain the cellular structure of plants, but also declared that it was composed of separate cells, which he designated "utricles.'; Thus did he foreshadow the cell-theory of plants. as developed by Schleiden in the nineteenth century. When it came to interpretations of his observations, he made several errors. Applying his often-asserted principle of analogies, he concluded that the vessels of plants are organs of respiration and of circulation from a certain resemblance that they bear to the breathing tubes of insects. But his observational work on structure is good, and if he had accomplished nothing more than this work on plants he would have a place in the history of botany.

Work in Embryology. Difficult as was his work in insect anatomy and plant histology, a more difficult one remains to be mentioned, viz., his observations on the development of animals. He had pushed his researches into the finer structure of organisms, and now he attempted to answer this question: How does one of these organisms begin its life, and by what series of stops is its body built up? He turned to