Page:Popular Science Monthly Volume 14.djvu/708

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THE POPULAR SCIENCE MONTHLY.

more numerous, the proportion being 62·91 per cent, to 37·09 per cent. Mantegazza is inclined to suppose that at a period more or less remote the third molar will disappear from the human jaw.

A New Plant.—A botanical discovery of considerable interest is announced in a letter, written by Dr. Beccari, from Sumatra. It is a gigantic aroid, which can only be compared with the Godwinia discovered by Seewann in Nicaragua. Dr. Beccari is as yet unable to determine the genus, but he believes it to be a Conophallus. The tuber of one plant was 1·40 metre in circumference, and two men were hardly able to carry it. From the tuber, as in the genus Amorphophallus, only one leaf is produced, which in form and segmentation does not differ much from that genus. But the dimensions are very different indeed. The stalk at the base in one instance was 90 centimetres in girth, was slightly less at the apex, and reached the height of 3·5 metres; its surface was smooth, of a green color, with numerous small, white dots. The three branches into which it was divided at the top were each as large as a man's thigh, and were divided several times, forming altogether a frond not less than 3·1 metres long. The whole leaf covered an area of 15 metres circumference. The spadix of a plant found in fruit had the stalk-dimensions just given; the fruit-bearing portion was cylindrical, 75 centimetres in girth, 50 centimetres long, and was densely covered with olive-shaped fruit 35 to 40 millimetres long, and 35 millimetres in diameter, of a bright-red color, each containing two seeds.

Advantages of Oral Teaching.—It would not be easy to compress within equal space a greater amount of practical common sense than we find in a recent communication entitled "Our Schools," printed in "The Examiner." "I believe," writes the author, "that one of the great stumbling-blocks to boys is want of oral teaching, in a popular style, particularly among little boys. It is a notorious fact that the grown-up world generally learns geography and history by means of newspapers and reading accounts of current events with the aid of the maps which are published from time to time for the purpose. and, if boys were taught in the same popular manner at the commencement of their education, it would do lasting good. We must all remember the dreary toil of mastering geography by learning a quantity of details out of a book about the number of inhabitants, names of rivers, the trade, the religion, and manners and customs of any country, without any means of impressing facts on the mind, while history becomes a positive treadmill when left to a boy's private reading. When the Prince of Wales went to India, if any one with an attractive manner of talking had taken a series of cartoons simply showing the rivers, the principal cities and mountain ranges, and some of the pictures published in the illustrated papers, he could, by arousing deep interest, have made the way easy for acquiring a fuller, more complete knowledge. The same mode of teaching would apply to the late European wars, the Indian famine, or any other great national event or calamity. We do this kind of thing in business matters every day of our lives in committees, on trials, and in all important transactions. It should be the same with boys; they should be interested in their subject before being set to master its drier details, which would, by this very introduction, lose much of their dryness."

Retentive Memories.—A number of instances of great retentiveness and accuracy of memory are recorded by a writer in "Chambers's Journal." Among the names mentioned is that of Dr. Robert Chambers, whose power of memory was very extraordinary. For example, on a certain occasion he was heard to say, "This day forty-seven years ago, at twenty minutes past two o'clock, I was passing" such a number of such a street, and met such and such a one. The author finds in Sir Walter Scott and in Charles Dickens a like accuracy of memory, and to this attributes no small share of their success as story-writers. Then a case is cited from one of Dr. Carpenter's writings of a clergyman who, on visiting Pevensey Castle, felt convinced he must have seen it before, and that when he did there were donkeys under the gateway, and some people on top of it. On inquiry he ascertained that he had been there with a picnic party, who made the excursion on donkeys, when