With this history we must stop for to-day, and I expect it will be many weeks before you have thoroughly examined the specimens of each kind which I have put in the aquarium. If you can trace the spore-cells and urns in the seaweeds, observe the polyps in the Sertularia, and count the number of mouths on a branch of my animal fringe (Sertularia tenella); if you make acquaintance with the Thuricolla in its vase, and are fortunate enough to see one divide in two; if you learn to know some of the beautiful forms of diatoms, and can picture to yourselves the life of the tiny inhabitants of the Flustra; then you will have used your microscope with some effect, and be prepared for an expedition to my pool, where we will go together some day to seek new treasures.
[1] The slice given in Fig. 64 is from a broader-leaved form, U. lactuca, because this species, being composed of only one layer of cells, is better seen. Ulva linza is composed of two layers of cells.
CHAPTER IX
THE DARTMOOR PONIES,
OR
THE WANDERINGS OF THE HORSE TRIBE
ut away the telescopes and microscopes to-day, boys, the holidays are close at hand, and we will take a rest from peeping and peering till we come back in the autumn laden with specimens for the microscope, while the rapidly darkening evenings will tempt us again on to the lawn star-gazing. On this our last lecture-day I want you to take a journey with me which I took in imagination a few days ago, as I lay on my back on the sunny moor and watched the Dartmoor ponies.