146 C. M. CHILD. 



SUMMARY. 



The axial gradients in many plants and animals can be very 

 clearly and beautifully demonstrated as color gradients by the 

 use of low concentrations of K 2 Mn 2 O 8 , the color being due to the 

 reduction of the permanganate to MnO 2 by protoplasm. 



Axial gradients have been demonstrated by this method in all 

 axiate organisms thus far examined including several algae, a 

 diatom pseudothallus, four species of protozoa, various hydroids, 

 hydromedusae and their developmental stages, a siphonophore, 

 actinians, developmental stages of polyclads and echinoderms, 

 axiate appendages of polychetes, and ascidian tadpoles. 



HULL ZOOLOGICAL LABORATORY, 

 UNIVERSITY OF CHICAGO, 



October, 1918. 



REFERENCES. 

 Child, C. M. 



13 Studies on the Dynamics of Morphogenesis, etc. VI., The Nature of the 



Axial Gradients in Planaria and their Relation to Antero-posterior Domi- 

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 '14 The Axial Gradient in Ciliate Infusoria. BIOL BULL., XXVI. 

 '153 Axial Gradients in the Early Development of the Starfish. Am. Jour. 



Physiol., XXXVII. 



'i5b Individuality in Organisms. Chicago. 

 'i6a Axial Susceptibility Gradients in the Early Development of the Sea 



Urchin. BIOL BULL., XXX. 



"i6b Axial Susceptibility Gradients in Algse. Bot. Gaz., LXII. 

 'i6c Experimental Control and Modification of Larval Development in the 



Sea Urchin in Relation to the Axial Gradients. Jour, of Morph., XXV. 

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BULL., XXXI. 

 'i7a Susceptibility Gradients in the Hairs of Certain Marine Algae. BIOL. BULL., 



XXXII. 

 'i7b The Gradient in Susceptibility to Cyanides in the Meridional Conducting 



Path of the Ctenophore Mnemiopsis. Am. Jour. Physiol., XLIII. 

 '170 Experimental Alteration of the Axial Gradient in the Alga, Griffithsia 



bornetiana. BIOL. BULL., XXXII. 

 'i7d Differential Susceptibility and Differential Inhibition in the Development 



of Polychete Annelids. Jour, of Morph., XXX. 

 Crozier, W. J. 



'i8a On Sensory Activation by Alkalies. Am. Jour. Physiol., XLV. 

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 Golodetz, L. 

 '14 Die Darstellung der Reduktionsorte und Sauerstofforte der Gewebe. 



Zeitschr. f. wiss. Mikr., XXX. 

 Golodetz, L., and P. G. Unna. 



"09 Zur Chemie der Haut. III., Das Reduktionsvermogen der histologischen 



Elemente der Haut. Monatshefte f. prakt. Dermatol.. XL VI II. 



