GENERAL ro.V>7///.7,-| Tin vs. 



638 



Fig. 298. 



in tlie medullary substance; in the interior are seen a great number of 

 aiterial capillaries. The nerves an- derived from the sympathetic system. 



Tlu- atlerent lymphatics, where they enter the gland, communicate with 

 tin; alveoli which correspond to 

 the cortical substance ; these al- 

 ar.' connected by the cords 

 of the central layer, and the latter 

 are united, in their turn, to tlie 

 tilve di of the opposite side of the 

 cortical substance, from which the 

 efferent ramuscules spring. The 

 lymph, therefore, tiaverses every 

 part of the gland, and during this 

 very tortuous course becomes 

 charged with solid particles. 



Certain glands have a much 

 more simple structure, being en- 

 tirely composed of lymphatic capil- 

 laries rolled up on themselves in 

 clusters, and anastomosing in net- 

 works. These capillaries arise 

 from the divergent arborisation of 

 the afferent vessels, and are contin- 

 uous with the convergent branches 

 which, by their union, form the 

 efferent lymphatics. The organs 

 h-ive received the name of false 

 /luitilx, thou-'h they are really PORTION OF THK MKOI-I-LARY SUBSTANCE OF THE 

 lymphatic glands. In support of M ^*uc GLAND OF AN ox, THK ABTKBY 



.. e i. L L . , ., . OF WHICH IS 1NJIXTKI) WITH eillloMATK OF 



this assertion, it may be said that IjKAI) . MAGNIKI|;I) :{(m I(IAM1 , TKKS . 



Me. lullary suhstanre with capillary network, 

 tine reticuluin of connective ti-siie. and a few- 

 lymph corpuscle.-; l>, >>, Sii|K>rtidal lymph- 

 path, traversed hy a ruticulum of nucleated 

 cells (.- ,-). with numerous anastomosing ji|- - 

 loii^ations. The lymph corpuscles have for 



the most part 1 11 removed; </. i/. Train-cilia- 



composed almost e.\cliisi\cly of unstri|>ed mus- 

 cular ti-siie; ,/. A small medullarv cord, or 

 hridire, containing a blood-vessel and numerous 

 lymph cnrpu 



" in descending the animal series, 



Be the glands becoming more 

 and more simplified, and trans- 

 formed at a great numlicr of points 

 into an interlacing of vessels. In 

 birds, they only occupy the base 

 of the neck and th" entrance to the 

 chevt. forming in all the other 

 regions simple plexuses; in rep- 



1 and tishes. the lymphatic glands 



disappear altogether, and the plexuses that replace them are themselves m>t 

 at all complicated." Sappey. 



I'M i-AUATioN OK THK I/YMriiATiG VESSELS. The lymphatic networks cnn only be 

 studied u'ter I.Hvini: IM-CII till, d with m> rcury hy means of injection; lmt as thi- opeia- 

 tiori is n..t ii.-nally pra.-ii.-i-d )>y the pupils for whom this \->k is written, the m.*!.- ,.f 

 pci!'.,rmiii"; it will only ! trac.-il in a t. \s words. 



The appaiatns in us-- ci moists of a ";lawn tuhe continuc<l l>y ft fh-xildi- unc. wlit<-)i 



ta inf. rim- t-xtr. mity nn iron t4ip and a line caiinla. al> . of imn, r (I- tt- r ) irla.-*. 



'I'o apply t i- a|ipuratns, the tube oiiv'ht t" !< Mi.-|K-nd. d and then tilh d with mei.-in \ ; 



muln is then seized hy tin- ripfht hand, kei-jtini: it parallel to tin- BMnfctaoeWfl 



wish ml hinyiiiir it in the mo.-t superficial luyer of that iiiemhrane. The 



.1 t\ of tin- c niiila is thus intnluce.l into tin- niul.-t of tlie me.shi-s of ti.i- 1\ mphatio 



m -toik, :ind necessarily wounds some of thi- capillaries wliich compose it. In o|n-nin^ 



ury i.s all .w.-d ( \\\\ into the c ip'llari.-- l.y th.- s dutii.n- of ,- .ntinmty 



.ii, and lills them in the m. st perfect m inner. 'J In- lympimtic pi. xnsi-s heinir 



