August 30, 1901.] 



SCIENCE, 



337 



wood as a material in the constructive arts. Future 

 possibilities of forests when coal is gone. 



6. A study of the common cereals and the condi- 

 tions of soils and climate demanded by each species. 



Mr. Goode is unanimously recommended to the 

 Faculty of Philosophy by Group Committee X. for the 

 degree of Doctor of Philosophy. 



Professor ConJclin, Presentor. 

 John Eaymond Murlin was born in Auglaize 

 County, Ohio, April 30, 1874. He received his early 

 education in the public schools of Mercer County, 

 Ohio, at the Ohio Normal University, and in the Pre- 

 paratory Department of Ohio Wesleyan University. 

 He entered the Ohio Wesleyan University as a fresh- 

 man in March, 1 894, and received the degree of Bache- 

 lor of Science in June, 1897. During his senior year 

 he was instructor in physiology and histology, and 

 the following year was instructor in physiology and 

 zoology in the same institution. He entered the De- 

 partment of Philosophy of this University, September 

 24, 1898, electing his major and one minor in zoology, 

 and one minor in botany. In 1899 he was granted a 

 Harrison Fellowship at Large in zoology, this ap- 

 pointment carrying with it candidacy for the degree 

 of Doctor of Philosophy. He was reappointed to the 

 same Fellowship for the current year. 



He has completed in this University twenty and 

 one-fourth standard courses, and has in addition de- 

 voted practically his entire time for three years to 

 laboratory work, the summers of these years being 

 spent in the Marine Biological Laboratbry at Wood's 

 Holl, Mass. The laboratory work which Mr. Murlin 

 has done would probably be equivalent to sixty stand- 

 ard courses. He has satisfactorily passed written 

 examinations in zoology on May 28 and June 2, 1900, 

 with Professor Conklin and Dr. Moore ; on May 28 

 and 29, 1901, with Professor Conklin and Assistant 

 Professor Montgomery, and in botany on May 30, 

 1900, with Professor Macfarlane. 



Mr. Murlin has presented a thesis entitled, 'The 

 Digestive System of the Land Isopods, with special 

 reference to the Morphology of Absorption and Secre- 

 tion,' and has deposited with the Dean a copy of it, 

 together with the money necessary to print it. Its 

 scope may be outlined as follows : 



Structural and functional changes in the intestine 

 of two common genera of land Isopods have been 

 followed during (1) growth ; (2) the process of shed- 

 ding the chitinous lining ; and (3) the stages of food 

 absorption. The intestine might be described as a 

 cylindrical conduit, the wall made up of a single 

 layer of cubical elements of the same size, and lined 

 with a homogeneous but porous intima. These ele- 

 ments, the cells, are very large, being visible in adult 



specimens even to the naked eye. The minute struc- 

 ture of both cell-body and nucleus is seen with high 

 powers of the microscope to be alveolar, /. e., the 

 protoplasm is composed of very small semi-fluid 

 vesicles, between which is a homogeneous interalve- 

 olar substance and supporting fibers, running from 

 the inner to the outer side of the cells. During growth 

 of the animal the intestine increases in size both by 

 multiplication (direct cell-division) and by enlarge- 

 ment of the cells. When the lining (chitin) is shed, 

 the fibers on the side of the cells next the lumen 

 disappear, and in their place is seen a fluid substance, 

 hy the hardening of which the new lining is laid down. 



In the digestion of proteids, as is well known, sev- 

 eral stages intervene between the insoluble condition 

 in which the food enters the stomach, and the readily 

 soluble condition which it must reach before it can 

 be assimilated. Hitherto the food has been traced 1o 

 the absorbing cells, and has been identified in differ- 

 ent form in the blood of many animals after having 

 traversed the cells. The purpose of this study was 

 to follow the food through the cells. Albumose, the 

 first soluble stage in the digestion of albuminous 

 foods, is recognized in the cells eight hours after feed- 

 ing. The food in this form traverses the interalveolar 

 spaces, and may accumulate in the outer side of the 

 cell from sixteen hours after feeding, onward. The 

 course of the food through the wall of the intestine 

 is not visibly influenced by the cell-structure except 

 in a purely mechanical manner. Albumose is not 

 found in the blood of the animal, which bathes the 

 outer side of the intestinal wall ; the inverse change 

 back to albumen must therefore be effected before the 

 food reaches the circulation. A finely granular sub- 

 stance comes from the nucleus and is associated with 

 albumose in its passage through the cell ; it probably 

 acts on the albumose either to carry the digestive 

 process farther, or to begin the inverse process (syn- 

 thesis toward albumen), or both. 



Carbohydrates are readily digested in the intestine, 

 dextrose, the soluble form of starch, being found 

 twenty-four hours after feeding. In the absorption 

 of fats the indications are that splitting-up by ferment 

 action into fatty acid and glycerine takes place in the 

 lumen of the intestine, and synthesis by ferment action 

 takes place within the cell. 



The digestive secretion is first recognized in imma- 

 ture cells of the ' liver' in the form of (zymogen) 

 granules. During the growth of these cells the 

 granules increase in size, become looser in structure, 

 more soluble in certain reagents, and more stainable. 

 The secretion is set free into the lumen of the gland 

 in the form of a proteid fluid by mere evacuation of 

 the cells, or by fragmentation and dissolution of 

 their luminal ends. Discharging cells are found from 



