126 



BIOLOGICAL PHYSICS 



are disposed to think that the lachrymal glands (Figs. 48, 

 49), and other aquiferous textures within the orbits are 



FIG. 49. FKONT OF THE LEFT EYELIDS WITH THE LACHRYMAL CANALS 

 AND NASAL DUCT EXPOSED. 



i, i, upper and lower lachrymal canals, showing towards the eyelids the narrow bent 

 portions and the puncta lachrymalia ; 2, lachrymal sac ; 3, the lower part of the 

 nasal duct ; 4, plica semilunaris ; 5, caruncula lachrymalis. 



likely to derive their supplies of fluid from the same 

 source, and along the neurilemmar inter-spaces surrounding 

 their nerve supplies. 



FIG. 50. SEMIDIAGRAMMATIC VIEWS OF THE INNER SURFACE OF THE 

 RIGHT CEREBRAL HEMISPHERE OF THE FCETAL BRAIN AT VARIOUS 

 STAGES OF DEVELOPMENT. (From Schmidt.) 



i, 2, and 3, are from foetuses of the respective ages of eight, ten, and sixteen weeks ; 

 4, from a foetus of six months, a, lamina terminalis or part of the first primary' 

 vesicle which adheres to the sella turcica ; b, section of the cerebral peduncle 

 as it passes into the thalamus and corpus striatum ; the arched line which 

 surrounds this bounds the great cerebral fissure ; c, anterior part of the fornix and 

 the septum lucidum ; d, inner part of the arch of the cerebrum, afterwards the 

 hippocampus major and posterior part of the fornix ; e, corpus callosum very short 

 in 3, elongated backwards in 4; in 4, _/J the marginal convolution; f, calloso- 

 marginal fissure ; g, gyrus fornicatus ; /', the parieto-occipital fissure descending 

 to meet the calcarine fissure; I, olfactory bulb; F, P, O, T, frontal, parietal, 

 occipital and temporal lobes. 



If all this be true and we see nothing anatomically, 

 histologically, or physiologically, in the organisation and 



