1889.] MICROSCOPICAL JOURNAL. 151 



Short Notes in Practical Biology. — Amcpba. 



By VIDA a. LATHAM, F. R^ M. S., 



UNIVERSITY OF MICHIGAN. 



In this paper will be given a few short and concise hints to students 

 who may be interested in this pleasant study, as the summer will afford 

 a good time for material. I have often found that students who, if pos- 

 sible, can stay indoors will try to get out for a walk wdien some slight 

 inducement be given them or there is an object to be found. Not onlv 

 does this render a walk pleasant, but it improves one's health and spirits, 

 and, what is more, it cultivates observation and patience. 



Definition. — Biology is the studv of living things. ,J;(*o=life, 

 /(Y(;s':=science. Without pausing to discuss the exact meaning of the 

 word " life," we agree that biology is the study of those forms of mat- 

 ter that are by common consent called living. 



Pla7t of Work. — Nothing should be more strongly impressed upon 

 the voung student than the necessitv of svstem in his work. There 

 should be a place for everv newly-acquired fact, whether it be gained 

 by reading, from a lecture, or from the observation of the student him- 

 self. He should accustom himself to say as each acquisition is made, 

 " that fact belongs to such a division of my plan, fits in under such and 

 such a head." The adoption of such a plan aids in the following wavs : 

 (i)* By fixing the foct more firmly in the mind, for the very eftbrt to 

 think where the fact is to be located concentrates attention more fully 

 upon it and renders it more easilv remembered ; (2) by rendering the 

 student more able to recall any special fact that mav be required ; bv 

 enabling him in an examination to reproduce his knowledge with much 

 greater readiness. Asked for the life-historv of a hvdra. he has not to 

 rack his brain in frenzied fashion in order to collect a number of isolated 

 facts, but goes steadily through his plan placing truths under their re- 

 spective heads, and finds at the end that notiiing of importance has been 

 omitted. I use the following outline, which mav be altered to suit 

 requirements : 



{a) vStructure, {b) digestion, (c) absorption, {d) circulation, (r) 

 respiration, {f) secretion, {g-) nervous system, {h) sense organs, (/) 

 motor organs, {k) reproduction, (/) development, (w) classification. 



Practical Work. — Every plant or animal must be seen, examined, 

 dissected, and drawn. 



Amoeba — a Protozoon («;/£;, 5(/j=I change) — is an animal which con- 

 sists of only one cell, the equivalent of a single cell of any of the tis- 

 sues of a higher animal. 



a. STRUCTURE. 



I. Occurrence. — Amoeba may be found in sea water and in fresh, 

 stagnant water, in mud, in damp earth. They can be obtained bv ex- 

 posing a piece of raw meat covered with a little water to the sunlight 

 until all the water has nearly evaporated. They fnay then be found in 

 the small quantity of water left, or by mincing veiy small portions of 

 the surface of the meat with water. When a small quantitv of the 

 material containing Amopbte is introduced into a glass aquarium and 

 some fresh water added a thin film usually appears on the sinface of 

 the water. This film is usually composed of small organisms, some 

 of which are likely to be Amoeba. Take with a pipette a small portion 

 of the film, allow a drop to fall on a glass slide. Lay a narrow strip 



