Prof. Trelease's Lecture.

An enthusiastic audience filled Boylston Hall to overflowing last night to hear Prof. Trealease deliver his lecture on the fertilization of flowers. Prof. Trelease had a thorough control of his subject and held the attention of the audience for an hour and a half; he spoke in a clear voice, and was ably aided by Mr. Huntington who kindly volunteered to manage the stereopticon which Prof. Cook generously lent for the occasion. Although the lecture was a thoroughly scientific one, it was not at all too abstruse to be be followed by the novices in the audience.

The lecturer began by illustrating the internal mechanism of a flower. Every flower contains stamens and pistils, - the male and female organs of generation, - and an ovary or calyx in which the fruit or seed is generated. The, stamen is the pollen producing organ; this, when placed on the stigma and style of the pistil, excites the secretions of that body which make their way to the ovary to the undeveloped seeds within. The lecturer divided flowers into four groups: those self-fertilizing, and thost fertilized by wind, water, and animal life.

The first group is small. A very few flowers like our Violet, are completely fertilized before the bud opens, - the stamen and pistil coming into contact.

Examples of the wind-fertilized plants are Indian Corn, Poplar and Maple trees, etc. In the case of corn the so-called "silk" is the pistal, and the pollen on the "tassel" is shaken off by the wind and conveyed to the ears, thus fertilizing them. Pollen is often carried for half a mile in this way.

The wind fertilized trees have staminate and pistilate flowers, and the wind conveys the pollen to the pistils which are made very broad in order to catch it. Leaves on these trees usually appear after the flowers, or else are needle shaped so as not to interfere with the passage of the pollen.

Many flowers, such as eel grass and the water-lilies are water-fertilized. The staminate and pastilate flowers are born near the root of the plant under water, the latter rise on long stems to the surface, and the former breaking off, rise and fertilize them.

Birds, insects and snails, he continued, do not work gratuitously, being either allured by food, warmth or shelter. They enter flowers either for these purposes, or for that of depositing their eggs. Flowers are peculiarly adapted for various kinds of insect propagation; gnats taking some of the long tubular ones, and being restrained by a kind of a trap till their work is finished. Bees and balancing flies are fond of tubular flowers. Moths fertilize Orchids, carrying pollen balls clinging to their tongue or eyes. Humming-birds attack long necked flowers like the Trumpet Vine. Flowers allure these animal friends by colors and odors, and guide them by a beaten path to their goal; they discourage intruders by ingenious safeguards.

Prof. Trelease closed his lecture by saying that however the subject of botany was considered, either as the result of a direct order of the Creator, or that of slow growth and self development, it was worthy of the greatest attention and study of mankind.