Dearborn, A Laboratory-Course in Physiology Based on Daphnia etc. 



XV. Taxes: Daphnia, Cyclops, etc. 



A. Chemotaxis: Paramecium, Anurea. 



B. Phototaxis: Daphnia, Ameba. 



C. Thermotaxis: Paramecium, Oxytricha. 



D. Electrotaxis : Cyclops. 

 XVI. The Senses: Daphnia. 



A. Vision: range and acuity. 



B. Touch. ,,Reflex" removal of irritants. 



C. Taste. 



D. Smell? 



XVII. Embryology: Daphnia. 



A. Summer eggs and their development. 



B. Winter eggs. 



C. Parthenogenesis. 



D. The brood-sac and its secretion. 



E. Coalescence of embryonic eyes. 



F. Comparison of functional rates in embryos and in 

 mother. 



XVIII. Animal Behaviour: Paramecium, Hydra, etc. 

 XIX. The Mental Life of the Animalcules. 



One finds here basal and important principles of universal 

 physiology, and the ingenuity of other experienced physiologists 

 would surely indicate and define many principles more. The essen- 

 tials of much physiology certainly are here. 



A second possible feature of this manner of teaching elemen- 

 tary physiology has been alluded to by implication already: the 

 transparency and the smallness of the animals used make 

 more striking and easy of acceptance the essential uni- 

 fication of parts into the animal whole. In Daphnia this is 

 notable in the interest a first viewing of the animalcule invariably 

 excites whether in man or child. One actually sees for example 

 the blood corpuscles that are kept in circulation by the heart pulsa- 

 ting under the observer's eye; and the intestinal peristalsis can 

 be actually seen to advance up the gut in relation with the pul- 

 sations of the_digestive_gland. Here is unification too obvious to 

 be missed even by thec-areless child. Without a comprehension 

 of the interdependence of his bodily parts he can learn neither to 

 understand himself nor how to keep well! 



A third advantage of such a course certainly lies in the sim- 

 plicity and the inexpensiveness of the apparatus requir- 

 ed. Many elementary schools have compound microscopes and 

 every school or even every student could provide at least a strong 

 pocket-lens, which might be made to suffice. Beyond the micro- 

 scope the apparatus required is almost nothing not afforded by 

 XXXII. 19 



