Document Type



Compression and other distortions in microtome sections of animal tissues have recently been the object of studies by Dempster (1) and Marengo (2). Dempster stated that compression of animal tissues "embedded and cut in 52°C. m.p. "Biloid" paraffin varied from 15% in thick sections (20-25µ) to over 50% in identical material sectioned between 5 and 10µ. He varied the clearance angle of the knife from l-6°, tried several kinds of paraffin with different melting points and used a number of cutting speeds to determine the amount of compression under routine laboratory conditions. Marengo, however, found that compression was slight in 3-5µ sections of bull testis embedded and cut in 56-58°C. m.p. "Biloid" paraffin to which small amounts of bayberry wax and beeswax had been added. By an ingenious method of direct measurement he demonstrated that compensatory thickening, an index of compression, was practically insignificant when bull testis was cut in hard paraffin with a knife angle of 7°. These studies upon animal tissues should not be expected to serve as a criterion of similar compression on microtome sections of plant materials. Plant tissues having firm cell walls and including vascular elements not found in animals, might be expected to exhibit less 9ompression. The present study is the beginning of a series of experiments in which attempts will be made to measure compression in microtome sections of various plant tissues.

Publication Date


Journal Title

Proceedings of the Iowa Academy of Science





First Page


Last Page



©1945 Iowa Academy of Science, Inc.



File Format




To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.