342 PULPY SUBSTANCE OF THE BRAIN. 



ing to a queen bee, by modifications of external circumstances, 

 are consistent with the original existence of every part. Thus, 

 as it is clear that one part may produce another which did not 

 exist, that the fibrous portion of the brain may proceed from the 

 pulpy. 2. As all the fibres of nerves are seen to begin in pulpy 

 substance, and, the greater the mass of grey substance, the greater 

 number of fibres are seen to proceed from it; and as, whenever 

 in the brain or spinal chord an enlargement occurs in the fibrous 

 band, there is an accumulation of pulpy matter, that the pulpy 

 appears destined for the production and support of the fibrous 8 ; 

 and this not only in regard to nerves, but to the encephalon and 

 spinal chord. For, whenever a portion of the fibrous part of the 

 brain increases, a quantity of pulpy substance is found at the 

 point of increase; just as wherever a branch springs in a tree, 

 its origin is in a mass of soft substance, so that the diameter of 

 all the branches exceeds that of the stem, and they are not 

 divisions of it. Again, before fibres appear at all, the brain and 

 other nervous parts are altogether pulpy and greyish. For, though 

 Dr. Tiedemann asserts that the pulpy substance of the spinal 

 chord is not formed before the fibrous, Gall refutes him in the 

 most masterly manner, showing that he allows the chord to be at 

 first fluid, then *' soft, reddish, and sprinkled with numerous small 

 vessels," and that at length, in the course of the first two months, 

 or about the beginning of the fourth month, fibres are seen. 

 These are Tiedemann's own words; and yet he fancies he opposes 

 Gall, who contends for the very same thing, saying, " it is the 

 pulpy, gelatinous, non-fibrous substance sprinkled with innumer- 

 able blood-vessels, secreted the first by the pia mater, which 

 engenders, nourishes, and multiplies the nervous fibres." Dr. 

 Tiedemann also objects that, if the swellings or ganglions of the 

 chord were found first to engender the rest, and the nerves cor- 

 responding with them, they should be found in the embryo ; but 

 that they are not. Certainly this cannot be expected, replies Gall, 

 before the chord becomes consistent, or the period for the pro- 

 duction of nerves has arrived ; and when the great nerves of the 

 extremities begin to form, and not before, can we expect that the 

 pulpy substance which produces them will be observed. 1 Dr. Tiede- 



* 1. c. 4to. vol. i. p. 44. and p. 242. 



1 See Gall, 1. c. 8vo. t. vi. p. 65. sqq. A masterly refutation, but apparently 

 unknown to English anatomists. 



Dr. Bellingeri fancies that the pulpy substance is for sensation, the fibrous 

 or motion. I think it is Dr. Foville who fancies that the pulpy is for the pecu- 



