UTERIA. 



[ 798 ] 



UVELLA. 



maize (U. maidis, fig. 788) has minutely 

 echinate spores, 1-2500" in diameter. 



It is curious that when U. Anthe- 

 rarum attacks a dioecious plant, as Lychnis 

 dioica, it causes the abortive stamens to be 

 developed, and then finds its place in the 

 new anthers. 



Sedges are infested by Ust. wceolarum 

 with dark-brown and Ust. olivacea with 

 olive-coloured spores (Uredines, Br. Fl.) 



Fig. 788. 



Portion of a spike of Maize infested with Ustilago 

 maidis. Some of the lower grains perfect and mature : 

 above these, female flower with abortive ovaries. The 

 projecting bodies are grains which have become de- 

 formed by the Ustilago developed within them. 



Ust. antherarum, growing in the anthers of 

 Caryophyllacese, has violet-coloured spores. 

 Many other species are described by Tulasne, 

 several of which have occurred in Britain. 



BIBL. Tulasne, Ann. So. Nat. 3. vii. 73, 4. 

 ii. Io7 ; Berk. Br. Fl. art. Uredo; Ann. N. 

 H. 2. v. 463. 



TJTE'RIA, Mich. See THYRSOPOBKLLA. 



U'TERUS. The substance of the uterus 

 consists of longitudinal, transverse, and 



Fig. 789. 



oblique unstriated muscular fibres, inter- 

 woven with imperfectly developed areolar 

 tissue resembling that in the stronia of the 

 ovary. 



Three layers of muscular fibres are de- 

 scribed, but they are intimately connected. 

 Those in the cervix are principally trans- 

 verse or circular ; and immediately beneath 

 the mucous membrane at the mouth of 

 the uterus, the transverse fibres form, a 

 sphincter. 



The muscular fibres are 

 from 1-COO to 1-400" in 

 length, fusiform, with elon- 

 gate-oval nuclei, and very 

 difficultly separable on ac- 

 count of the large amount of 

 areolar tissue intermingled 

 with them. 



The epitheliumis simple 

 and ciliated. The mucous 

 membrane of the body has 

 no papillae, but hero and 

 there some folds, and con- 

 tains numerous tubular or 

 uterine glands resembling 

 the Lieberkiihn's glands of 

 the intestines, their caecal 

 ends being simple, bifurcate, 

 or spiral, and consisting ^ of 

 a basement-membrane with 

 cylinder-epithelium. ^ 



In the cervix are situated 

 glandular depressions of the 

 mucous membrane, which 

 secrete a transparent tena- after parturition, 

 cious mucus ; some of these S^J^Sjf? 

 are closed, and form the y, globules of fat. 



OVUles Of Naboth. Magnified 



The lower third or half 350 diameters, 

 of the canal of the cervix 

 contains papilla covered with ciliated epi- 

 thelium. 



During gestation the uterine elements, 

 especially the muscular fibres, as also the 

 vessels and probably the nerves, become 

 enlarged and more numerous, from new 

 formation (fig. 790). 



All three of the coats of the veins of the 

 pregnant uterus contain muscular fibres. 

 After parturition, many of the muscular 

 fibres undergo fatty degeneration, and be- 

 come absorbed (fig. 789). 



BIBL. Kblliker, Mikr. An. ii. ; Chrobak, 

 Strieker's Hist. iii. 



UVEL'LA, Bory, Ehr. A genus of 

 Flagellate Infusoria, fain. Monadina. 



Char. Bodies without an eye-spot, 



