RECORDS OF MEETINGS 265 



The count at 37° C. for such air is about half that of 20° C. and 

 rarely over 50 per cubic foot. 



The air of occupied spaces shows larger average numbers of micro- 

 organisms and greater fluctuations. The 20° C. count may average over 

 100 per cubic foot and may reach 700 or more. The 37° C. count aver- 

 aged over 50 in the factories and offices. Mouth streptococci are more 

 abundant in the indoor air, ranging from 20 to 40 per 100 cubic foot 

 of air. 



Dr. Scott stated: A. Lowering of the temperature causes a reduction 

 in the rate of oxygen consumption, B. Oxygen was consumed more rap- 

 idly in tall, narrow vessels of water than in broad, shallow ones. C. 

 Fishes kept in dark vessels apparently consume oxygen at a less rapid 

 rate than those exposed to light. D. Some forms show more resistance 

 to low oxygen supply than others. This is particularly true of inverte- 

 brates. Eespiration ceases altogether, and commences again if the speci- 

 men is returned within certain" time limits to aerated water. The toad 

 fish and killifish live in water with low oxygen content, while a butter- 

 fish and menhaden quickly succumb to reduction of oxygen supply. E. 

 Most marine invertebrates consume oxygen at a very low rate ; fishes at a 

 much higher rate; with amphibia the rate is between that of inverte- 

 brates and fishes; the rate with mammals and birds is relatively high, 

 that of birds being extremely high as compared with anatomically lower 

 forms. 



Professor Pike stated that the changes which occur in animals and 

 plants may be divided as follows : 



1. Changes of form — ^growth and development, ontogenetic and phylo- 

 genetic. 



2. Changes of position — the phenomena of movement. 



3. Changes of material and energy. 



There are many contributions to the study of evolution from the stand- 

 point of changes in form and changes in position and but few from the 

 point of view of changes in matter and energy. The effect of environ- 

 ment upon the organism is manifested through the changes in matter 

 and energy. Injurious substances in the environment may slow down 

 or stop the processes occurring in living matter. The failure of moisture 

 may mean death or encystment. A low temperature means a slowing 

 down of life processes, a suspension of activity or death. Distribution of 

 an organism is restricted to a region in which a given set of conditions 

 exists. Herbert Spencer pointed out the fact that some organisms have 

 acquired a certain degree of independence of the environment. My own 



