290 



APPENDIX 



functioning of all the other organs of the body. A scheme of the organs 

 of internal secretion, to be complete, must embrace every organ, and so 

 far only the barest beginning has been made in this study so important, 

 so necessary for the understanding of development and inheritance. Prob- 

 lems of development and inheritance cannot be solved until these physio- 

 logical questions are answered. 



As for the bearing of these processes upon Heredity, the internal secre- 

 tions of the body appear to Mathews to constitute strong evidence against 

 the existence of such things as inheritance by means of structural units 

 in the germ which represent definite characters in the body. We see in 

 the internal secretions, he observes, that every character in the body involves 

 a large number of factors {i. e., determiners). The shape and size of the 

 body, the coarseness of the hair, the persistence of the milk-teeth, a ten- 

 dency toward fatness — all these may easily depend on the pituitary body, 

 on the thyroid, and on the reproductive organs, and these — ^in their turn 

 — are but the expression of other influences played upon them by their 

 surroundings and their own constitution. An accurate examination shows 

 the untrustworthiness of any such simple or naive view as that of unit 

 characters. 



NOTE VII 



TABLE — RELATIONS OF THE PRINCIPAL GROUPS OF ANIMALS 

 REFERRED TO IN THE TEXT 



Phylum 

 Protozoa 

 (the simplest 

 animals) 



Class PAGES 



Rhizopoda [ Lobosa — Amceba, etc 93, 112, 114, 116 



Foraminifera (porous-shelled protozoa) 



32, 103, 115 

 Radiolaria (siliceous-shelled protozoa) 115 



Mastigophora 112, 115 



Infusoria — ciliates, etc 112, 115 



Sporozoa 



PORIFERA 



(sponges) 



1 Calcarea Calcareous sponges 



^Non-Calcarea f Siliceous " 



\ Fibrous " 



130 



CcELENTERATA f 'Hydrozoa f Hydroids — millepores 113 



< Siphonophores 

 [ Graptolithida 



^Scjqihozoa Jellyfishes 120, 129, 130 



^Actinozoa Sea-anemones, corals, sea-fans, etc 103 



Ctenophora 



^ Fossil and recent forms. 

 All other classes listed are as yet unknown in the fossil state. 



