20 



SCIENCE. 



[N. S. Vol. XXI. No. 523. 



may be regarded as a composite, formed 

 by the fitting together of the series of sys- 

 tems, and while in some instances we have 

 more or less accnrate notion of the way 

 such a system appears— as, for instance, in 

 the case of the skeleton— yet a much better 

 understanding of the relation of the soft 

 parts would follow an attempt to extend 

 this method of presentation, and to con- 

 struct phantoms of the body in the terms 

 of its several systems in some way which 

 would show us the system in question as 

 an opaque structure in a body otherwise 

 transparent. This is, of course, the final 

 aim of the various corrosion methods, or 

 those which depend on injection or differ- 

 ential coloration of structures which may 

 be viewed in three dimensions. 



When the vascular, lymphatic, nervous 

 and glandular systems can be thus ex- 

 hibited for the entire body, or for the 

 larger divisions of it, it will be possible to 

 see the human form transparently, and to 

 see it whole ; a feat difficult to accomplish, 

 but worthy of earnest endeavor. The de- 

 velopment of such phantoms should serve 

 to make more impressive the familiar fact 

 that in many organs and systems the total 

 structure is built up by a more or less 

 simple repetition of unit complexes, as, for 

 example, the liver by the hepatic lobule, 

 the bones by Haversian systems, and the 

 spinal cord by the neural segments. 



If we pass now from the consideration 

 of the systems of tissues to that of their 

 structural elements, we enter the domain 

 of histology and cytology. Starting with 

 the diffoi-entiation of the tissues by means 

 of empii'ical staining incthods, investiga- 

 tors have gradually coiiie to appreciate the 

 chemical processes which underlie the vari- 

 ous color reactions, and as we know now, 

 there already exist inethods for determin- 

 ing in the tissues several of the chemical 

 elements, such as iron, phosphorus, etc., to 

 say nothing of the more or less satisfactory 



identification of complex organic bodies 

 by means of definite reactions. This be- 

 ing the case, it is possible to imagine repre- 

 sentations of the body built up on the 

 basis of these micro-chemical reactions, 

 representations which would show it in the 

 terms of iron or in the terms of phos- 

 phorus, thus yielding us an image which 

 might be compared with that obtained by 

 aid of the spectroscope when the picture 

 of the object is taken by means of one out 

 of the several wave-lengths of light which 

 come from it. 



The contemplation of the multitudinous 

 opportunities for investigation and com- 

 parison which appear within this field, 

 lead us to pause and inquire what is prop- 

 erly the purpose of all this anatomical 

 work; for without a strong guiding idea 

 we are liable to repeat the errors of earlier 

 generations, and merely accumulate ob- 

 servations, the bearing of which is so re- 

 mote from the actual course of seientifie 

 progress that the investigations are mainly 

 useful as a mental exercise for the individ- 

 uals who conduct them. Anatomical results 

 begin to have a real meaning only when 

 correlated with physiology, and when we 

 learn that a tissue with a certain structure 

 is capable of performing given functions, 

 we feel that we are really bringing our 

 anatomy into touch with the life processes. 

 It is to aid in the accomplishment of this 

 end that men devote their lives to anatom- 

 ical work. With the variation that we 

 find everywhere in organic structures, it 

 should be and is possible to discover by 

 comparison what variations in the struc- 

 ture of a tissue or a cell are accompanied 

 by the best physiological responses. It 

 is along this line that we must necessarily 

 work in order to reach human life either 

 through medical practise or through other 

 avenues of approach, for in the end the 

 object and purpose of all science is to 

 ameliorate the unfavorable conditions 



