Ch. XI] 



MODELS FROM SERIAL SECTIONS 



413 



specimen before it was imbedded and sectioned being used as a 

 guide by which the correct form of the pile of sections can be tested. 

 Finally the whole is welded into one by the use of hot wax or a hot 

 instrument. Models which illustrate complex internal structures are 

 difficult to prepare, but numerous devices will occur to the worker, as 

 the representation of blood vessels and nerves by strings or wires. A 

 large model will need much support which 

 can be given by wire gauze, wires, pins, 

 or paper, according to the special needs. 



A practical method for wax modeling 

 was first published by G. Born, Arch. f. 

 Mikr. Anat., Bd. xxii, 1883, p. 584. The 

 most detailed statements of improvements 

 of the method have been published by 

 Born (Bohn u. Oppel), 1904, and by Dr. 

 F. P. Mall and his assistants. See con- 

 tributions to the Science of Medicine, pp. 

 926-1045. Proceedings of the Amer. 

 Assoc. Anatomists, 1901, 14th session 

 (1900), p. 193. A. G. Pohlman, Zeit. wiss. 

 Mikroskopie, Bd. xxiii, 1906, p. 41. 



To overcome the difficulty of cutting 

 out the wax plates, Dr. E. L. Mark of 

 Harvard University uses an electrically 

 heated wire moved rapidly by a modified 

 sewing machine (Amer. Acad. Arts and 

 Sciences, March, 1907; Science, vol. xxv, 

 1007; Anat. Record, April, 1907). 



Fig. 245. Kingsbury's 

 Movable Stand for Slide 

 Trays and Reagents. 



(From the Anatomical 

 Record). 



r, r, r Reagent boards with 

 bottles and jars. 



st, si Slide trays. 



The stand has furniture 

 slides on the legs and is easily 

 moved on the floor. 



Susanna Phelps Gage Blotting-Paper Models 

 § 668. Comparison of wax and paper models. — Wax has certain 

 inherent defects for models: It is expensive, heavy, and fragile. It 

 is easily deformed by the temperature of summer, and the amount of 

 time necessary for the preparation of the plates is great. A wax- 

 plate machine is expensive and bulky. 



It therefore seemed worth while to see if there was do! some other 



