144 



ERECTILE TISSUE. 



M. Jacobson,* who has recently published a 

 description and figures of the young Filaria 

 Medinensis, compares the body of the mother 

 to a tube or sheath inhabited by the young 

 ones; and, after a careful examination of three 

 individuals, we have equally failed in detecting 

 either generative or digestive tubes within 

 the muscular sac of the body. The external 

 tunic of the body is a firm subtransparent 

 elastic integument, which, examined under a 

 high magnifying power, presents fine trans- 

 verse striae, occasioned most probably by ad- 

 herent muscular fibres. Within this tunic 

 and readily separable from it are the longitu- 

 dinal muscular fibres, which are arranged in 

 two fasciculi, separated from each other by two 

 well-marked intervals on opposite sides of the 

 body, which are indicated by an impression 

 (or furrow, as the worm dries by evaporation) 

 on the exterior surface. When from long 

 maceration the crisp outer integument has 

 become separated from the longitudinal mus- 

 cular bands, these might be mistaken for two 

 tubes contained loosely within the cavity. 

 I believe that these muscular bands are the 

 tubes fibrineuses, described by Dr. Le Blond f 

 as the alimentary canal and intestine in the 

 fragment of Filaria Medinensis, which he 

 dissected. In a small Filaria Medinensis, 

 containing no vermiculi, we have also failed 

 to discover any distinct tubes for digestion or 

 generation. 



It is interesting to observe that the young 

 of the Filaria Medinensis do not resemble the 

 parent in form ; one extremity is obtuse, the 

 body slightly enlarges for about one-fourth of 

 its length, then gradually diminishes to within 

 a third of the opposite extremity, which is 

 capillary and terminates in the finest point. 

 The enlarged part of the worm contains a 

 granular substance, and is coiled upon itself, 

 and presents a distinct but minute annulation 

 of the integument : the capillary extremity is 

 smooth, transparent, and generally straight. 

 The Trichocephalus dispar closely resembles 

 in its external form the fatus, if it be such, 

 of the filaria Medinensis. 



BIBLIOGRAPHY. Redi, Osservazioni intorno 

 agli animali viventi che si trovano negli animali 

 viventi, Firenze, 1684. Block, Abhand. von d. 

 Erzeugnng Eingewerdwurmcr. Berl. 1782. Goeze, 

 Versuch einer Naturgeschichte der Eingewerdwur- 

 roer, und Nachtrag dazn. Leipz. 1782-1800. Val- 

 lisneri, Conaiderazioni ed espericnze intorno alia 

 gencrazione de vermi ordinarj del corpo umano. 

 Padova, 1782. Werner, Vermiura intestinalium, 

 &c. brevis expositio. Lcipz. 1782. Retzitu, Lec- 

 tiones publica: de Vermibus intestinalibus, Holm. 

 1786. Schrauh, Verzeubniss der bisherigen hin- 

 langlich. bekannten Eingeweidwiirmer, Munch, 

 1788. Rudalphi, Observ. circa vermes intestinales, 

 '2 fane. Greifsw. 1793-95. Rudoljthi, Entozoorum 

 8. vennium intcstinalium historia naturalis, 2 in 3 

 vol. Amst. 1808-9. Rudolphi, Entozoorum Synop- 

 sis, Berl. 1819. Treutter, Obs. pathol. anat. ad 

 helmiuthologiam Corp. humani. Leipz. 1793. Zeder, 

 Anleitung zur Naturgeschichte des Eingeweidwiir- 



* Nouvelles Anuales du Museum d'Histoire Na- 

 turelle, torn. iii. p. 80, pi. v. 



t Quelqucs Mateiiaux pour servir a 1'Histoire 

 des Filaires et des Strongles, 8vo. 1H36. 



mer. Bamb. 1803. Olfert, De vegctativis ct ani- 

 matis corporibus in corporibus viventilms reperiun- 

 dis comment. Berl. 1816. Fischer, Bievis Entozo- 

 orum s. verm, intest. expositio. Vienna-, 1822. 

 Bremser, Uebcr lebende Wiirmer in lebenden Mcns- 

 chen. Wien, 1819; trad, en i'ran9ais. par MM. 

 Grundler et de Blainville, Paris, 1825. liremier, 

 Icones Hclminthorum Systema Rudnlphii illus- 

 trantes, Wien. 1823. Joerdens, Entomologie und 

 lielminthologie des Mensch. Koerpers. 2 Bde, Hof. 

 1801-02. Lidth de Jeude, Recucil des figures des 

 Vers intestinaux, Leid. 1829. Cloquet, Anatomie 

 des Vers intestinaux, Paris, 1824. Creplin, Observ. 

 de Entozois, Greifesw. 1825-29. Schmals, De Eu- 

 tozoorum systemati nervoso, Lcipz. 1827. Ejta, 

 Tabulae anatomicae Entozoorum, Dresd. 1831. Le 

 Blond, Quelques materiaux pour servir a 1'histoire 

 des filaires et des strangles, Paris, 1836. Mehlis, 

 Obs. Anat. de distomate hepatico et lanccolato, 

 Gbtting. 1825. Nordmann, Mikrographische Bei- 

 tr'tige, 2 Bde. Berlin, 1832. Jacobson, in Nouv. 

 Annales du Museum d'Hist. Nat. torn. iii. Klein, 

 in Philos. Trans, for 1730. Carlisle, in Trans, of 

 the Linnean Society, vol. ii. Laennec, in Bulletin 

 des Sciences de 1 Ecole de Medecine, An xiii. 

 Home, in Philos. Trans, for 1793 ; Fruch, in 

 Miscell. Berolinensia, torn. iii. ; and for further re- 

 ferences to numerous papers on the natural history 

 of particular families and species, vide Heust i 

 Repertorium, &c. Scientiae Naturalis, torn. i. Zoo- 

 logia, &c. Gbtting.; the first vol. of Rudolphi's 

 Entozoorum historia naturalis, and Wieaemann't 

 Archiv fiir Naturgeschichte und Vergleichende 

 Anatomie. 



(R. Owen.) 



ERECTILE TISSUE, (telaerectila; Fr. 

 tissu erectile ; Germ, das erectile, oder schwell- 

 bare Gewebe,) a structure composed prin- 

 cipally of bloodvessels, intimately interwoven 

 with nervous filaments. This tissue in its ordi- 

 nary state is soft, flaccid, and spongy; but 

 when influenced by various causes of excite- 

 ment, whether these consist of stimuli directly 

 applied, or operating through the medium of 

 the sensorium, it exhibits the faculty of admit- 

 ting an influx of blood much greater in quantity 

 than what is sufficient for its nutrition, and in 

 virtue of which it suffers a state of turgescence 

 giving rise to a swollen condition, with more 

 or less of rigidity and increased sensibility of 

 the organs into the structure of which it enters, 

 and which state has been long known by the 

 name of erection. From the property of under- 

 going erection peculiar to this tissue, Dupuytren 

 and Kullier first applied to it the term erectile, 

 and the propriety of this distinguishing appel- 

 lation is now very generally admitted by anato- 

 mical authors. 



The erectile tissue is developed in various 

 degrees in the several parts of the animal 

 economy in which it occurs; it is abundant 

 and particularly evident in the corpora caver- 

 nosa penis, corpus spongiosum urethra;, clitoris, 

 nymphce, plexus retiformis, the nipples of the 

 mammary glands, less marked in the red 

 borders of the lips, &c.; it also enters into the 

 structure of the papillae of the skin and the 

 villi of the mucous membranes which possess 

 the property of becoming erected in the per- 

 formance of their functions, as is exemplified in 

 the papillre of the tongue. These consist of the 

 pulpy terminations of nerves enveloped by this 

 tissue; in their unexcited state they appear 



