1912.] NATURAL SCIENCES OF PHILADELPHIA. 147 



membranelles, flagella) are affected only after a much longer time. 

 In Vorticella, for example, the power of contraction is lost in less 

 than a minute, while the membranelles may beat normally for three- 

 quarters of an hour or longer. Sometimes a converse relation in 

 the effect of carbon dioxide on these two classes of structures appears, 

 the contractile elements being first stimulated and then paralyzed 

 and the vibratile ones often temporarily stopped and then started 

 again. 



George Howard Parker, Sc.D.: "Sensory Appropriation, as 

 illustrated by the Organs of Taste in Vertebrates."* 



In addition to smell and taste, ordinarily regarded as chemical 

 senses, vertebrates possess a third sense which may be called the 

 common chemical sense and which is exemplified in man in the 

 sensitiveness of the mucous surfaces of the eye, nose, etc. Contrary 

 to the opinion of Weber, solutions of odorous substances introduced 

 into the human nose can be smelled. Hence Nagel's contention 

 that the nose of the water-inhabiting vertebrates is an organ of 

 taste rather than an organ of smell is unfounded and the recent work 

 of Parker and of Sheldon has shown conclusively that fishes scent 

 their food with the nose as air-inhabiting vertebrates do, i.e., the nose 

 in vertebrates, water-inhabiting as well as air-inhabiting, is a distance 

 receptor. A comparison of the chemical responses of catfishes, with 

 and without organs of taste, shows that the common chemical sense 

 is more closely related to the sense of taste than to the sense of smell 

 and that its receptors are the free-nerve terminations of certain 

 fibres in the spinal and cranial nerves. Of the three senses, smell, 

 taste, and the common chemical sense, the* most primitive is the 

 sense of smell, which probably represents the specialized and re- 

 stricted remains of a general chemical sense common to the whole 

 surface of the invertebrate ancestor of the vertebrates. By a 

 central migration of the cell body of these primitive olfactory 

 receptors of the general surface, the organs of the common chemical 

 sense were produced. These in turn appropriated groups of epider- 

 mal cells which in time became specialized into taste buds, and 

 thus arose the third and last of these chemical sense organs, the 

 organs of taste. 



John M. Macfarlane, Ph.D.: "The Relation of Protoplasm to 

 its Environment."* 



The simplest plants now living are the Schizophyceae and the 

 Schizomycetes, both composed of cells or cell chains with rich granu- 

 lar protoplasm, with or without a chromatophore, and either devoid 

 of a nucleus or with a granular chromatin rudiment of it. 



The species of the two groups now found in hot springs at tem- 

 peratures of 55°-75° C. are probably primitive types, alike on account 

 of their wide distribution over the world and their adaptation to 

 high temperatures. From these, there seem to have developed 



