POPULAR LECTURES.

Star (Christchurch), Issue 9912, 29 July 1910, Page 1

POPULAR LECTURES.

. HUMBLE .BUT USEFUL EARTHWORMS, The series of popular science lectyjres in connection witn Canterbury CoMege was continued last evening, when a large audience gathered in the College Hall to listen to a lecture by Professor W. B. Benham, of Otago University, on "The Natural History of an Earthworm." Mr H. J). Aclaiid, a member of the Board of Governors of the College, presided. The lecture was perhaps at a disadvantage from its unattractive title, hut/ having a. most intimate acquaintance with the anatomy and habits of the lowly earthworms and a nice turn of humour, the lecturer was able to make his subject thoroughly interesting and exceedingly popular. Professor Benham used a large number of lantern slides prepared from photographs, and diagrammatic representations of microscopic observations, and with the aid of these he was able to introduce his audience to a wealth of information regarding the structure and importance of earthworms. He said that ho had himself devoted twenty-five years to the study of earthworms, and, though it might be found that his lecture was a resume of Charles Darwin's observations, he had been able to add some facts from other points of view. Professor Benham proceeded to describe the anatomical structure of a worm, saying that it possessed organs of a most elaborate oharacter, which were as efficient for the purposes of the worm as those of higher orders of animals were for them. Its wonderful digestive system, which included a pair of kidneys in each of the 200 odd segments, its brain, of which the function was not to exert control over the rest of the nervous system, but to receive impulses from the nob above the mouth, its lack of the senses of sight, hearing, smelling and tasting that was compensated by a sensibility to light and delicate vibrations and an ability to distinguish palatable from unpalatable foods, were all described in a most interesting manner. Experiments regarding the ability of the worm to repair a wound had resulted in the knowledge that a new head would develop if the point of division were between tho head and the twentieth segment, and in the same way the limitation of the growth of a new tail was the thirtieth segment. Why this was so had not been ascertained. Emphasis was laid on the value of earthworms in increasing the fertility of the soil by raising the subsoil to the surface. Urquhart had decided in 1883 that the number of worms per acre in pasture lands in Auckland was 784,080, while in 1886, Smith had calculated the number of worms in the soil of North Otago and South Canterbury at 556,920. Urquhart had estimated the dry weight of worm castings as 736.554 tons per acre per annum, and it had been decided that every particle of earth to a depth of two or three feet was brought to the surface in the form of worm castings onco in twenty-soven years. Tho castings of worms were remarkably rich, and there was no doubt that tho fertility of the globe that made it habitable."bv man was duo to the activity of the lowly and despised earthworms.

Professor Benham was frequently applauded, and at the conclusion of the lecture a vote of thanks was accorded to him by acclamation.