SYSTEMATIC SYNTHESIS OF TISSUES INTO ORGANS. 275 



OF THE GRAY TISSUE evidently is to pack in the smallest 

 space a large amount of gray tissue, the cells of which 

 shall be in connection with white fibres. 



661. IF A HORIZONTAL SECTION THROUGH THE LOWER 



PORTIONS OF THE CEREBRi BE MADE, or if a perpendicular 

 section of the brains be made on the line of the fissures, 

 or if the corpus callosum be cut out, numerous small 

 ganglia will be revealed as located in the lower central 

 portions of the Brain and in front of the cerebelli. 



662. THE CENTRAL GANGLIA CAN ALSO BE EXPOSED 

 by raising. up and turning forward the back part of the 

 cerebri, and cutting a few fibres that confine them. 



663. THE ARRANGEMENT OF THE GANGLIA CAN BE 

 BEST UNDERSTOOD by constructing the Brain from below; 

 beginning with the spinal cord, where it enters the cra- 

 nium, ganglia of small size are added to it, enlarging 

 its size into the oblongata ; to the back part are added 

 the cerebelli, from the right to the left of which, around 

 the upper part of the oblongata, extends the pons (16, 

 Fig. 188), above which other ganglia are placed, some of 

 the fibres from the cord and nerves extending into them 

 all, and into the cerebelli, while the remainder extend 

 upward and forward into the great ganglia, the cerebri. 



664. ACCORDING TO THE SUPPOSITION, THE CEREBRI 

 WOULD BE LIKE two great pear-shaped masses, and the 

 whole chain of ganglia would present a very irregular 

 outline, not susceptible of protection, and altogether 

 uncouth. 



665. Hence THE MASSIVE CEREBRI ARE, so to speak, 

 FOLDED BACK, over, upon, and by the side of other parts, 

 slightly overhanging the cerebelli, and quite covering 

 in the central ganglia. 



666. WHERE THE SURFACE OF THE CEREBRI COME IN 

 CONTACT WITH THE CENTRAL GANGLIA, they do not ad- 

 here to them, but both surfaces are free, and moistened 



661. What ? 662. How ? 663. How ? Construct the Brain from below 

 by successively adding ganglia, 664. What ? 665. How ? 668. What said of ? 



