ij-i ' COMPARATIVE ANATOMY. 



of a paired organ lying on ritln-r side of the fauces, that is, in the 

 IV.MOII when- tlie mouth passes into the phannx: they consist of 

 a retiform (adenoid) connective-tissue ground-substance enclosing 

 a number of lymph-corpuscles, which are arranged in so-called 

 follicles. 



Lyinphoid tissue plays a very important part in the body-ea\ ity 

 of Fishes mid Amphibia. Apart from thr alimentary canal, it is 

 pivsc'iit. in considerable (piantity in the region of the. urinary and 

 -emtal -lands, which are often regularly embedded in it (e.g. Dipnoi). 

 The mass of lymphoid tissue on the heart of the Sturgeon, and 

 possibly also the so-called "fat-bodies" of Amphibia and Rip 

 rilia, and the " hibernating gland " of certain Rodents, may b. 

 placed in this category. 



The agglomeration of a number of these follicles gives rise to 

 those structures which are spoken of as "lymphatic glands." 

 These are always interposed along the course of a lymphatic 

 trunk so that an afferent and efferent vessel to each can be dis- 

 tinguished. They probably appear first in Birds, and are most 

 numerous in Mammals, where they are present in abundance in 

 various regions of the body; they differ greatly in size. 



The spleen, which is present in almost all Vertebrates, is 

 closely related to these structures. It usually lies near the 

 stomach, though it is occasionally met with in other regions of 

 the intestinal tract, as, for instance, at the commencement of the 

 rectum (Anura, Chelonia). In some cases (e.g. Sharks) it is broken 

 up into a number of smaller constituents. 



Both the lymphatic glands and the spleen have to do with the 

 formation of lymph-cells, but their complete physiological function 

 is as yet by no means clear. 



llir.l.KH.KAI'llV. 



AVK.US, II. Jicitr. zur Anatomie wid Physiology der l>i'jiocr. Jena'sche Zeiischrift 

 jar NaturwissenschotfUn, lid. XVIII. N. Folge, Bd. XL 1885. 



BKDHAKH. !'. K. Note on the Prw/i/v />/' n,i AntiTior Abdominal r<in in Kcli'idn. 

 /'/<ic. Zool. Hoc. 1884. On the Heart of Apt' rii.,-. Hi, I. issf.. 



MI i \^, K. V. See numerous 1'aprrs 0,1 ///, I'lt.-n-ii/n/- Stist,>/n of /'/..//* mul Ain/iliHiin 

 in tin: Morphol. Jahrb. lid. VI. 1880, lid. VII. 1881, 'and I'.d. VIII. 1882. 



(i'lMi-KUTZ, ('. Ui'lirr Her:: tnul T>litt!.-r<ixJ<nif In I nacktcn Amphibicn. Arrh. f. 

 Annl. iiinl l'/ii/sii>/,i,/i,' (Physiologische Alithi-ilun^\ 1.SS1. i'riiis ronlains a 

 niasti'rly dt/sc-.ri|itiuii uf tlii' . \iialniny and I'liysinln^y nt - llii- Heart of Anura.) 



1,. \VKKSTEK, K. RAY. OIL /I/' /'.'/; //; Hi- //<'// .//" Omithorhynchus '/i<ii-iit/i>,ru . 

 compnrrif ////// tinw uf Mini mul /// HnMiii. ////// *oir Observations mi //*< /-'w.^' 

 Ovalis. Proc. Zool. Soc. 1882. On the Right Cunlin,- I'nlr,- <>f l-'.<-lii<hin <m<l 

 Ornithorhywliu*. H>i<l. 1883. On tl/, //./;// dcscrihnl /// friifiwr ,/; 

 1841 as that, f . \ />! ri/x. Ibid. 1885. On tin I!i<ilit Cardiac I '! r< of the ,s/nr///i /;. 

 of Apteryx di sanded by Sir Richard Owen in 1841. Ihiil. issfi. 



M 180AONI. -I'i-il'iiii'- i/' it ii iinrni'fc sur lesystimcil-'s m twins, lymphatiqufs. Sifiiin-. 

 1784. Vasorum lymphaticorum corporis humani historia ct iconographia. 

 Benia, 1787. 



MULLEK, .1. Ui-lii'r die Lymphherzen '// ./////<////-//. .////. /'. Aunt. n. 

 54. 



Mi IM-.I:, Y\'. -f r <'' rdenfeineren 



