TARGIONIA. 



[ 629 ] 



TARGIONIA. 



are usually deposited dm-ing the ecdysis, the 

 exuvise serving as a protection to them 

 during the process of hatching. The young 

 resemble the parents. 



The Tardigrada resemble some of the Ro- 

 tatoria in reviving after having been kept 

 dried for years. 



Genera. Emydium, Macrobiotus, Milne- 

 sium {Arctiscon, doubtful). 



BiBL. Doyere, Ann. des Sc. nat. 2 ser, 

 xiv. 269, xvii. 193, xviii. 1; Dujardin, x. 185; 

 Vogt. Zoolog. Briefe, i. 496 ; Kaufmann, 

 Siebold and KoUiker's Zeitschr. iii. 220. 



TARGIONIA, Mich.— A genus of Pelliese 

 (Hepaticaceae), characterized by the almost 

 sessile, globose capsule arising from the end 

 of the midrib of the under face of the frond, 

 which is somewhat fleshy, smooth, deep- 

 green, purplish at the edges, and forms large 

 patches on rather moist but exposed banks. 

 The frond has an epidermis on both faces, 

 with stomata and intermediate parenchyma; 

 the midi'ib is only apparent beneath, and 

 has radical hairs, with purple scales. The 

 perichsete originates from this rib, on the 

 under surface, rising to the upper side (fig. 

 722). When mature, it is globose, of dark 



Fig. 722. 



Fig. 723. 



Targonia hj'pophylla. 



Fig. 722. Lobe of a frond with fruit. Magnified 5 

 diameters. 



Fig. 723. Pericheete opened, showing the globular spo- 

 range. Magnified 20 diameters. 



Fig. 724. Vertical section of a very young sporange. 

 Magnified 200 diameters. 



Rg. 725. A branched elater. Magnified 200 diameters. 



purplish colour and firm texture, and marked 



with a vertical prominent line or keel ; at 

 this line it ultimately splits into two valves 

 (fig. 723). From Hofmeister's recent ob- 



Fig. 726. 



Fig. 727. 



Fig. 728. 



Fig. 729. 



Fig. 730. 



Figs. 726 & 727. Groups of four spores, not qmte 

 mature. Magnified 400 diameters. 



Fig. 728. Parent-cells of spores and imperfect elaters, 

 from a more advanced fruit. Magnified 100 diameters. 



Fig. 729. The same. Magnified 200 diameters. 



Fig. 730. A single ripe spore. Magnified 400 diameters. 



servations, however, this envelope grows 

 up after the fertilization of the archegone, 

 which is originally naked in its upper half ; 

 hence it would seem to be a perigone. 

 Several archegones are found half-immersed 

 in the end of the midrib, and one of these is 

 converted into a fruit; the lower part be- 

 comes spherical, and the neck forms for a 

 long time a filiform point or style. This 

 epigone bursts irregularly and vertically. 

 The spherical capule emerges from it, but is 

 not protruded beyond the perichaete. The 

 globular capsule bursts irregularly at the 

 summit, and discharges spores and elaters 

 resembhng those of Marchantia (figs. 728 

 to 730). The antheridia are imbedded in 

 the midi'ib, opening on papillae on the 

 lower face. 



BiBL. Hook. Brit. Flor. ii. pt. 2. p. 105 ; 

 Corda, Sturm's Deutschl. Fl. Jungerm. pi. 

 30 ; Nees, Lebeimoose, iv. 



