easier than idiomatic Italian. The right book to begin on is a good murder story, such as one of Gaboriau’s, which are fortunately to be had in bad Italian. What would an old fashioned teacher of Greek and Latin have said to this! In my own case I feel that the difficulty of reading the classics was good discipline, and so far educational. In Henry Sidgwick’s method one is carried along by the detective business, and learns Italian words as a child picks up its own language, by context and re-iteration. It will be said that this method is not applicable to Latin and Greek, and that even if it were so, it would not be educative. I confess I do not expect my words to sink into the hearts of the teachers of what are unkindly called the dead languages. The great Moloch of examination has constantly to be supplied with human children, to say nothing of grown-up people. Some escape, but how many are reduced to ashes?
I have said nothing about what should have been my theme, namely, the beginning of the College year. To my thinking beginnings have something of the melancholy that seems more appropriate to endings. Sad associations tend to adhere to all that has the quality of periodicity. I for one feel this when spring once more puts on the familiar look with which our childhood and youth seemed to mingle on equal terms, but which upbraids us now we are no longer young.
And in a more work-a-day spirit Monday morning is sad. I think this is so because the conception Next Week is full of the ghosts of dead resolutions. No doubt it was on Monday mornings that Mr.
Shandy renewed his vow to have the hinge of the parlour door mended, which I think remained unrepaired to the end of the book.
But after all, this gloomy point of view belongs to the onlooker, not to the actors in the rhythm of things. Each particular Monday is a new-born entity, and doubtless feels a pleasurable excitement in its brief life. And to the actual snowdrops and winter aconites that pierce the cold ground, spring is a new and glorious experience. In this academic springtime (which chances to occur in autumn) the onlooker need have no morbid feelings, only perhaps a touch of envy of those whose College life begins to-day.
XIII
PICTURESQUE EXPERIMENTS
To those who have never made experiments on plants it may seem that ‘picturesque’ is an odd term to apply to laboratory methods. But to an experimentalist the adjective does not seem overstrained. There is not merely the pleasure of seeing a prediction verified—that may be experienced in more everyday matters. There is a peculiar delight in the discovery of a method of revealing some detail in the natural history of living things. I remember vividly the pleasure which I felt when I first tried the experiment on Sorghum, described in the essay on the Movements of Plants in this volume. [210] I hoped that the seedlings would curve in the elaborate manner shown in Fig. 4. But I had so little expectation of success that I did not explain the object of the trial to my laboratory assistant, and it came as a shock of delight when he told me that the seedlings had “curled up like corkscrews.” I do not think that it is an exaggeration to say, that this result is a picturesque illustration of the distribution of gravitational sensitiveness in plants. The instances in the present essay are not concerned with the movements of plants, and are so far less interesting, but I think the reader will not refuse them the same adjective.
We all know that in plants—from the smallest weed to the giant trees of America—there flows a stream of water from the root to the topmost leaf. Nevertheless, it is an experience to have ocular proof of this life-giving current. A branch of laurel is so arranged that it has to suck up the water it needs through a coarse thermometer tube, dipping into a beaker. The laurel does not wither, and we know therefore that it is continuously supplied with water. If the beaker is removed we shall see the absorption, for the thermometer tube does not remain full of water; a minute column of air is seen at its lower end which rapidly increases in size, and finally when the tube is emptied of its water-content, bubbles of air escape one after another into the larger tube, which contains the cut end of the branch. This, the simplest possible experiment, is nevertheless a vivid ocular proof of the laurel’s power of absorbing water. It can be shown that the sucking power of the branch depends on its leaves, for if these are removed the rate of the current is very greatly diminished. It can also be proved that it depends on some quality of the leaf surface, for if a new specimen is taken, and if the lower sides of its leaves are rubbed with vaseline, the rate of absorption will be seen to diminish very greatly. Greasing the upper surface of the leaves does not produce this result, and when we examine the two surfaces it is found that the lower one is riddled with innumerable microscopic holes (stomata), while the upper side of the leaf has no such apertures. The stomata in fact are the arbiters of what shall pass in or out of the body of the leaf;
they are the gate-keepers who regulate both export and import. They are known by actual inspection (with a microscope) to close at night: the result of this is that the evaporation of the leaves is much slower at night, and this is true when allowance has been made for the fact that evaporation is also checked at night by the dampness of the air.
