68 



FHHDKHK'K TILXKY AM) LTTHKH F. WAIJKKX 



presents itself is a single evagination in front of the posterior 

 commissure. The further differentiation of the epiphysis is 

 given by Lieberkiihn-'- in (inline and also in much more detail by 

 Mihalkovic/- 71 in 1X74 and 1S77. According to the description 

 of the latter, the principal change from the original saccular 

 evagination in the roof-plate consists in the conversion of the 

 original sac into a folliculated structure which presents many 

 alveoliform cell groups as a result of the rapid proliferation in 

 the walls of the original saccular anlage. Henrichs ('96) '" 

 found that the follicles first developed as hollow buds in com- 

 munication with the main cavity of the original epiphyseal 

 anlage. Later these buds become branched and in this way a 

 rich follicular system is developed. 



-Cor 



Fitf. 3"> The epiphyseal complex in an oinliryo of Sterna hirundo. according to 

 Klinrkowst n>riii. l.v.M . 



According to Henrichs, the paraphysis first appears as a solid 

 sprout and later acquires a lumen. Cameron" 1 showed in the 

 chick that the epiphyseal anlage is a double outgrowth, the left 

 being the larger. These two evaginations ultimately coalesce. 

 Practically the same condition is observed in amphibia. ( lar- 

 jano" 1 makes the observation which in the main covers the con- 

 ditions observed in birds, namely, that as compared with the 

 lower vertebrates the pineal body is a profoundly altered organ 

 in bird- and mammals. 



One M|' the authors in a recent work on the diencephalon re- 

 produces illustrations of reconstruction models which show the 

 development in the pineal region of <!<il!n* (jtillns. The first 



