20 ^1 Rccondructiou nf the Nuclear Masses in 



About in the middle of this dorsal ridge, in the caudal half of the nucleus, 

 its lateral slope becomes marked by irregularities in the form of slight furrows 

 and ridges. As one passes cephalad, these soon take shape in a marked 

 dorso-lateral projection which continues superiorly as a constituent portion 

 of the nucleus of Blumenau. This projection, in its lower portion, forms a 

 solid rectangular spur, but above, in its connection with the main cell-mass, 

 it becomes narrowed into a small pedicle with a broad, thin, lateral plate 

 lying in the midst of the fibers. This column can be traced cephalad to 

 the middle of the whole nuclear mass; in its upper portion it turns some- 

 what mesially, ending in a column of cells arising from its dorso-mesial angle 

 in the cephalic termination (figure 2). This new column rapidly connects 

 with an irregular bridge of cells, which covers the lateral aspect of the 

 dorsal ridge and runs to the mesial portion of the whole nucleus as it begins 

 to assume the dorsal plate with the nucleus fasciculi gracilis (figure 3). 

 Just lateral to this first dorso-lateral ridge is a ]n-ojection which begins 

 caudally somewhat cephalad to the first. This is in close relation to the 

 substantia gelatinosa (figure 2). Beginning below as a thin rectangular 

 mass of cells, this column rapidly widens into a rather broad lateral plate 

 with a small ]3edicle of cells connecting it with the main underlying nucleus 

 (figure 10). This plate marks the lateral limits of the nucleus and is shown 

 throughout its extent in figure 2. ?oon after its caudal origin it exhibits 

 a marked dorsal notch; then it overlies laterally, in a ventral projection, 

 the substantia gelatinosa. Coursing dorsally and cephalad from this ventral 

 projection, it finally loses its character in the broad, smooth, cephalic 

 termination of this lateral surface. Connected with this lateral plate, 

 just above its ventral projection, is an irregular triangle of cells elevated 

 somewhat above the main cell-mass (figure 2). The apex of this joins 

 the lateral plate, while its base lies just beneath (ventral) the lateral edge 

 of the dorsal plate. Its cejihalic margin is marked by a furrow on the ventral 

 side and by three irregular spurs on the dorsal; the furrow and projection 

 mark off the triangle from the smooth upper portion. The lateral surface 

 of this triangle is marked l\y a prominent gradual eminence and below by 

 a deep furrow. A sharp depression also occurs on its surface. Caudally, 

 the side of the triangle is marked by a deej) dorsal and a deeper, shari)er 

 ventral furrow, between which is a median ridge which projects ventrally 

 and somewhat caudally, to terminate near the lateral plate. In the ventral 

 fissure just mentioned, occur irregular lateral spurs and ridges, some running 

 u]) to the median ridge as it goes to terminate in a shallow groove marking 

 it off from the lateral i)late. The caudal limit of tlie dorsal furrow, which 

 delimits the lower side of the triangle, is constituted by the transverse bridge 

 of cells, already inentioncHl as continuing (he first dorso-lateral projection 

 to the dorsal i)late. 



This dorsal plate, the caudal mesial part of which the luicleus fasciculi 

 gracilis occupies, is shown both in figures 2 and 3. It is a smooth curving 



