OBSERVATIONAL LESSON IX 95 



exposed to the air and sun in order to whiten them or be put into 

 water containing bleaching powder. 



Make careful sketches of each limb and find out the names 

 of the chief bones, marking them on your drawings. 



The same plan may be made use of for all parts of the skeleton. 



Work of this kind will be found to be the best means of intro- 

 ducing one's self to the study of comparative anatomy, and at the 

 same time of forming an anatomical collection. It should be borne 

 in mind that a knowledge of the structure of an animal or a plant 

 can be of little real use if it does not lead to a comparison with that 

 of other animals and plants. 



A good exercise also would be to discover all the obvious points 

 of difference between a donkey and a horse, and afterwards the 

 resemblances or otherwise between these and other familiar animals 

 of large size might be sought for and found. Such general work 

 would be a good preparation for more particular observations such 

 as are indicated in the following chapter. 



