166 MANUAL OF HISTOLOGY. 



mens, and by careful focussing in silver preparations. Accord- 

 ing to Ranvier, they are connected near their point of union 

 by a very thin, elastic, fenestrated membrane. Below the layer 

 of elastic fibres is the connective tissue which forms the basis 

 of the membrane. It consists of fasciculi, which are straight, 

 or wavy, according to the degree of tension of the membrane, 

 or its fasciculi are held together by the elastic fibres, which 

 penetrate from the reticulum on each side. They usually pre- 

 sent a decidedly convoluted appearance in ordinary specimens, 

 and in consequence of the contiguous fasciculi not possessing 

 corresponding convolutions, clear interspaces are seen. Some- 

 times the fibres are very irregular in their arrangement. Ran- 

 vier claims that an interfascicular membrane can be demon- 

 strated here also. Ordinary flat, branching connective-tissue 

 cells are distributed through this tissue ; they lie upon and 

 between the fasciculi ; they are particularly numerous under 

 the endothelial layer. Lymphatic and blood-capillaries trav- 

 erse the interspaces and run upon the fasciculi. In the mesen- 

 tery and pleura they form a wide-meshed plexus ; in the peri- 

 cardium a close plexus. 



To see the features of the deeper portions to advantage, we 

 must remove the superficial endothelial layer before staining 

 with silver. 



'Klein's method of studying the omentum. Klein has de- 

 scribed a very careful process for doing this, and as he claims 

 it must be followed in detail to obtain the results at which he 

 has arrived, we reproduce it : "To prepare the omentum, a rab- 

 bit is killed by bleeding ; the stomach is exposed ; after having 

 pushed the intestine to the right side, the free surface of the 

 omeutum is pencilled several times from the large curvature 

 toward the diaphragm, with a fine camel's-hair pencil moistened 

 with fluid of tliQ abdominal cavity. After that, a or % per 

 cent, solution of nitrate of silver is allowed to flow over the 

 omentum from a large capillary -tube until the membrane has 

 become slightly milky (one or two minutes are generally suffi- 

 cient) ; after that, the stomach, together with the omentum, 

 spleen, pancreas, and a portion of the duodenum is cut out and 

 transferred to a large capsule with distilled water ; after some 

 time the water is renewed and the omentum is separated under 

 water, together with the spleen and pancreas, from the stomach, 

 with scissors, and is transferred to common water. Those parts 



