Page:Popular Science Monthly Volume 41.djvu/533

From Wikisource
Jump to navigation Jump to search
This page has been validated.

flowers of the more simple types gathered from the fields and furnished in abundance. Specimens of these plants, with blanks to fill in connection with the study of them, were taken home by the pupils.

At this session a report of the daily observations of the seedling bean, corn, flax, clover, and grass was submitted, and this work in the home garden continued. Twigs were assigned for study during the coming week, including a potato tuber that had been planted by each pupil the week before.

In the third lecture the subject of leaves was considered as to parts, arrangement, types of framework (venation), simple and compound forms, and various peculiar kinds of leaves were shown, as pitchers, fly-catchers, etc. It was in this lecture that some of the physiological principles of vegetation were brought out, including the taking up of the soil-water, its passage to the leaves, and the manufacture there, under the influence of sunlight, of the various compounds, as sugar, starch, and oil, that may be afterward employed in various ways in the economy of the plant.

The microscopic structure of the pulp of the leaf was shown by diagrams, and an insight was given into the cellular formation of tissues and their combinations into tissue systems. A very large number of kinds of leaves freshly gathered were exhibited to illustrate the many terms concerning foliage used in the classification of plants. In size and shape these varied through all gradations, from the mere scales of the asparagus and conservatory "smilax" to those of the garden rhubarb; and of the compound sorts, from the barberry with a single leaflet to those of the columbine.

The class-hour was devoted to the study of three plants, the flowers of which illustrated as many widely separated types. Thus the wistaria gave large peculiar blossoms of the pulse family, and in this connection a papier-maché model of the pea was dissected before the class, thus fully illustrating the several parts, even to the coats and embryo of the forming seeds, by means of a separate model of an enlarged pea-pod.

In the fourth lecture the flower was considered, and, while the parts had been previously learned in class-work with specimens, the functions of the various organs were now explained by means of diagrams and specimens. The many ways in which the pollen of one flower is brought to the pistil of another were illustrated, and the fact that close fertilization is the exception and not the rule emphasized. The pupils were made familiar with the various forms of flower arrangement by seeing the living examples. Perhaps fifty kinds of plants in bloom were shown to illustrate not only inflorescence but the form and union of the several parts of individual flowers.