892 DR. E, KLEIN. 
24, Several important questions present themselves in 
connection with these intralobular or intercellular lympha- 
tics: (a@) what is their shape and minute arrangement? (6) 
what is the nature of their wall? and (¢c) what is the rela- 
tion of the latter to the fat-cells themselves. 
As regards their minute arrangement it is that of a dense 
network whose meshes contain each one fat-cell. It is 
more difficult to ascertain their precise shape. At first 
sight these intercellular lymphatics appear as thin narrow 
canals, but on closer inspection it will be found that many 
are in reality sinus-like, surrounding the fat-cells for a 
larger or smaller section of their circumference, and there- 
fore possessing the shape of a portion of a spheroid. There 
are, however, some of them that are tubular, or approxi- 
mately so, their optical section being either circular or more 
or less oval.. 
In specimens of fat-tissue that had been successfully 
injected with asphalt-benzole, it will be found that the 
injection material indicating the intercellular lymphatics is 
distinctly contained in a well-defined space, there being a 
delicate but distinct membrane limiting it. But it is 
exceedingly difficult to ascertain what this membrane is, 
viz. whether an endothelial membrane representing the 
proper wall of the lymphatic, or whether it is merely the 
membranous connective tissue between the fat-cells. I am 
inclined to think the latter is the correct interpretation. 
In very thin and well stained sections, especially in teased 
ones, it is possible to distinguish, besides the fat-cells and 
blood-capillaries, a honeycombed matrix of connective tissue, 
which consists of flattened, nucleated connective-tissue cells, 
attached to a plexus of very thin fibre bundles derived from 
the interlobular septa. 
The successful injections make it highly probable that 
each of the above intercellular lymphatics is bounded by the 
fat-cell on the one side, and the intercellular honeycombed 
connective tissue on the other. Thus an analogy would be 
established between the ultimate lymphatics in the adipose 
tissue of the skin and those in the nerve trunks (Key and 
Retzius, ‘Studien in d. Anatom d. Nervensystems,’ &c.), in 
the latter the lymphatics between the neighbouring nerve 
fibres being separated by the endoneural connective tissue. 
I need hardly add here of how great importance in phy- 
vary greatly in this respect, for I have seen in the same section, both of 
human and dog’s skin, lobules, the greater part of which was injected, 
besides others in which only the peripheral portions showed the lymphatic 
injection. 
