1220 Journal of Applied Microscopy 



in less than a half hour." 4. Sense of smell. The most important olfactory 

 organs are the first antennse, but from the fact that there is some reaction to 

 olfactory stimulation after the removal of the antennae, it is thought that there is 

 a second organ for this sense. The author, however, did not succeed in pre- 

 cisely localising this second seat of " chemo-reception." 5. Color. Descrip- 

 tions are given of several color varieties of Amphithoe which exist in nature and 

 of the relation of the pigments in these varieties. The color changes adapting 

 the animal to its surroundings are less perfect than those shown by the prawn, 

 Hippolyte varians, as described by Gamble and Ashworth (Q. J. Mic. Sci. N. S. 

 43: 589-698, and this Jour. 4: 1182-1183). 6. Thigmotaxis. Amphithoe is 

 very strongly thigmotactic over all parts of the body. The author believes that 

 this thigmotaxis forms the basis of many of the animal's instincts. 7. The young 

 animals soon after hatching show most, if not all, of the instincts and peculiari- 

 ties of behavior exhibited by the adults. 



The paper is a good example of the tendency, which is becoming strongly 

 manifest, to return to the old " Natural History " view point, and, by the appli- 

 cation of modern methods of thought and investigation, to attempt to solve the 

 same sort of problems as those at which the " naturalists " of the early part of 

 the century worked. R. p. 



Yasuda, A. Studien uber die Anpassungsfa- This paper deals with the results of a 

 higkeit einiger Infusorien an concentrirte study of the power of acclimatisation 



A considerable amount of chemical 

 acclimatisation work has been done on the lower Algae and Fungi, but hitherto 

 there have been no extensive results from correspondingly low animal forms 

 available for comparison. Some of these needed results this paper presents. 

 As objects of experimentation the following species of infusoria were employed : 

 Eiiglena viridis, Chilomonas paramoeciiim, Mallotnonas Plosslii, Colpidimn colpoda, 

 and Faramoscium cmidatiwi. Cultures of these infusoria were put into solutions 

 of milk sugar, cane sugar, grape sugar, glycerin, magnesium sulphate, potassium 

 nitrate, sodium nitrate, potassium chloride, sodium chloride, and ammonium 

 chloride. The solutions of these substances were of different strengths, begin- 

 ning with very low concentrations and going up to those in which death occurred 

 immediately. In all cases observations were made on the length of time the 

 animal lived in the solution, the changes in structure, the effect on multiplication 

 and movement, etc. Detailed accounts are given of all experiments, but only 

 the most important results will be mentioned here. It was found that in isotonic 

 solutions all the different substances have nearly the same effect on the same 

 organism, but this relation is only an approximate one. The maximal limit of 

 concentration to which infusoria can become acclimatised is considerably lower 

 than in the cases of the Algae and Fungi. It is noteworthy in this connection 

 that Euglena showed the highest resistance capacity of any of the forms studied, 

 while it is of course, structurally, more closely related to the Algae than any of 

 the others. Increase in concentration is accompanied by a checking of the mul- 

 tiplication of the organisms ; by a retardation of the movement ; by an increase 

 in the size of the vacuoles, and chromatophores. In strong solutions the body 



