Developments in the field of Zoology during the last century will from the topic of a lecture by Rederick Macdonald, assistant professor in Zoology, on Thursday afternoon at 4 o'clock in the Large Lecture Room in the Biological Institute on Divinity Avenue. The lecture will be the fourth in a series on the progress of science in the last 100 years. The lecture is intended for the layman, so that a knowledge of Zoology will not be necessary in order to follow Dr. Macdonald's talk. It is expected that the lecturer will confine himself to the more familiar aspects of Biology. Professor Macdonald will probably explain at length Darwin's theory of the origin of species and the present conception of evolution that has grown from it. Another topic might be the Mendelian theory of the inheritance of characteristics, or Patseur's work on sterilization. A point of far-reaching importance that will posisbly be discussed is the greater collaboration of chemist and biologist.