ior and nfton ti'iniinatt's in a massive liook (Fig. 100 M, N, T). 



Wliilo oftiMi specific, the form of tlie spicules sometimes varies 

 anil more tlian one sjiecimen should ahvavs he studied. TIk' 

 writers found marked variation in spicular nuo plioloKv i" 

 ItirofiUiria immitin from an abnormal host (.nmskrat). In 

 addition to the normal type, a specimen in which the left 

 spicule blade was dcRenerate and another in which the left 

 spicule was absent were fouml in a sin^;le muskrnt. Such 

 tinilinf;s cause one to be scunewhat dubious of the numerous 

 species of filariids beinp; described at the present time, and 

 difTerentiated chiefly or wholly on diversity in spicular form. 



Differences in spicular niori)hology of related s])ecies may 

 be due to the degree of ceidialation, length and differentiation 

 of the shaft, or length and character of the blade. The blade 

 may be highly twisted as in Dichcihincmn (Fig. 100 V); 

 twisting and irregularity of the blade is p.-irticularly character- 

 istic of scune genera of the Trichostrongylidae (Fig. B, II, FF). 

 In addition the blade may be distally branched (Fig. 100 A, 

 MM^ or the flanges se]iarafed from the tube. 



The s|iicules are seldom very long in proportii.n to the body 

 in free living nematodes, one of the most outstan<ling excep- 

 tions to this rule being Miloiicholaimiis pri.ttiiini.i (Fig. 18) 

 in which the spicules are one-twentieth of the body length 

 (seven times as long as the anal body diameter). In parasitic 

 nematodes both the absolute and relative spicule lengths may 

 be many times greater. Thus, Wehr (103.3) found the two 

 equal sjiicules of Oilmitospinira cclinpenis (Spiruridae. Ha 

 bronematinae) to attain lengths of 1011 mm in specimens 

 If)- to 17 mm. Ransom (1004) found the left siiicule of 

 Go7ip;ilonrma infiluvicoltj to attain 17 to 10 mm in specimens 

 17 to 10 mm long (when retracted it twists and extends 

 through only three-fourths of the body length) ; in the same 

 form he found the riglit spicule to be only 0.1 mm long. Seu- 

 rat (1013) found that the left spicule of Trirameres inermin 

 reaches 1.187 mm in length and the right only O.Ol't mm in 

 specimens of a total length of 2.12.') mm (Fig. 100 V) . Long 

 spicules most commonly occur in representatives of the Spiru- 

 roidea, Filarioidea, Dioctophymatoidea, and Triehuroidea and 

 in those forms where the vagina is long and tubular. One 

 might attempt to correlate the length of the vagina with that 

 of the spicules were it not that one finds related species with 

 vaginae of about equal length and spicules relatively much 

 smaller. 



E. gub?:rnaculum and telamon 



The gubernaculum is by eommon definition a cuticular thick- 

 ening (selerotization) of the dorsal wall of the cloaca. This 

 definition is at once misleading. The gubernaculum is formed 

 from the wall of the spicular pouch. Proximally it is usuall.v 

 not in direct contact with the spicular cavity but is to be seen 

 as one or more plates in the wall of the spicular pouch; dis- 

 tally it may come to be the dorsal wall of the pouch or it may 

 pro.ieet free into the lumen (Fig. 110 U). The cuticle of the 

 gubernaculum, like that of the spicules, is in direct continxia- 

 tion with the pouch lining but unlike the spicules its sclero- 

 tized la.vers nia.v extend be.vond this covering internall.v. The 

 gubernaculum is essentially a plate in the groove of which the 

 spicules move. This condition is seen in many nematodes such 

 as Uliabditis (Fig. 40 L), Ancylostoma, etc. In others, how- 

 ever, the medial part of the plate may protrude into the spicu- 

 lar pouch separating the spicules. The posterior part of the 

 gubernaculum may then be termed the corpiix and the anterior 

 (medial) piece, the ciinciif:. Where this division occurs the 

 spicules are usually alate. In Spironoura (Fig. 110 A-U) the 

 gubernaculum divides near its proximal end giving off an 

 anterior branch (cuneus) which comes to lie free in the spicular 

 pouch; each dorsal spicular flange thus runs in a groove formed 

 by the cuneus and corpus of the gubernaculum. 



Hall (lOUl) proposed the term tidamon for an "ornamental 

 su|iporting structure" formed in the ventral and lateral walls 

 of the cloaca of Ili/oxlronfiitliis rtibiiliis (Fig. 100 (!). This 

 structure differs from the gubernaculum and si)iculeH in stain- 

 ing capacity and is more like the external cuticle. As may be 

 seen from sc'ction (Fig. 100(;(i-M.M) Hall's interpretation as 

 to the origin of the telamon is correct. If is an immovable 

 sclerofized part of the doacal wall which apparently serves to 

 turn the spicules posteriorly when they are prolruiled from 

 the spicular pcjucdi into the cloaca; otherwise the spicules might 

 lireak through the ventral doacal wall. Ordinarily such a pro- 

 tective structure would be unnecessary since the spicular pouch 

 orifice is imnu'diately opposite the cloacal opening but in the 

 Sfrong.vlina this is not the case. 



.Since Hall's original publication much confusion has resulted 

 from the applicafiijn of the terms gubernaculum and telamon, 

 Iiarf icularly in the Metastroug.vlidae. Camercui (1027) used 

 the term telamon for lateral iirofrusible branches (crura) of 

 the corpus which he described as "ornamental supiiorting 

 structures near the cloacal aperture'' (Fig. 110 FK.I.IJ. 

 Oebauer (1032) applied the term telamon to a medial ventral 

 selerotization of the spicular pouch (Fig. 110 EE) (the struc- 

 ture now known as the capitulum) and the term gubernaculum 

 to the unpaired and paired subdorsal sclerofizations of the 

 spicular pouch (corpus and crura). The structures involved 

 have been di.scussed by Shu 'Its, Orlov and Kutass (1033), and 

 by Dikmans (103.'>). A restudy of Priilo.ilronfmliis indicates 

 that the former authors correctly interpreted the entire com- 

 plex as a gubernaculum. The most important differentiation 

 between guliernaculum and telamon is that the IcUimon is 

 formed dirccllji from, the cloacal linini) while the fiubcrnacu- 

 hnn is formed from the spicular pouch. Though the guber- 

 naculum is primarily dorsal, it is also primarily medial, i. e., 

 it may develop proximal to the union of the spicular pouches 

 and, as in Spironoura it ma.y be composed of two or nuire parts 

 which are heavily sclerotized, these parts being joined by 

 feebly sclerotized regions. Thus the medial (ventral) piece 

 (Fig. 110 RS) termed the telamon by Gebauer, is actually a 

 part of the gubernaculum named the capHuhim by Shu 'Its, 

 Orlov and Kutass: the two posteriorly directed pieces (crura) 

 termed the telamon by Cameron and the gubern.'icul\im by 

 Gebauer are joined anteriorly to the capitulum by the un- 

 paired piece, corpus (Fig. 110 S). 



The confusion in terminology has led workers in other groups 

 to misapply the term telamon. Thus Steiner and Albin (1033) 

 termed the anterior parts of the gubernaculum (crura) of 

 Deontostoma caUfornicnm (Fig. 37, 4-5) a telamon. In so far 

 as the writers are aware, a true telamon does not exist outside 

 the Strongylina. 



The gubernaculum is often complex in free-living nematodes 

 and the various jiarts are worthy of discussion. Do ilan (1880) 

 described the gubernaculum of Enoplus communis (Figs. 110 

 A, C-D) as being composed of three parts: an unpaired medial 

 piece (termed cuneus, projecting anteriorly into the cloacal 

 cavity between the spicules) to which is joined posteriorly and 

 laterally a less sclerotized structure (corpus) which in turn 

 has two strongly sclerotized lateral pieces (crura). These 

 lateral pieces jiroject into the cloacal cavity on each side of 

 the spicules, each of which moves in a separate groove between 

 cuneus and crura, guided posteriorly by the corpus. In other 

 aphasmidians many variations of the above described arrange- 

 ment are known to occur. In Acautlwiiclius liviparus (Fig. 

 15 M), and Paracanthonchus caeciis (Fig. 100 Q R) the ends 

 of the crura are dentate while in Ciiatliohiimiis clon-flatus they 

 are denticulate. There is a marked diversity in develojiment 

 of the parts in closely related forms. Thus de Man (1880) 

 found the crura to be quite massive and apjiarently detached 

 (cuneus and corpus absent) in Paracanthonchus caccus while 



A-P — Spirnrtoitra nffine f Kathlaniidae] (Serial cross sections through 

 spicules and gubernaculum). Q-S — Protnslrnngiilus rupricnprae [Meta- 

 strongylidael (Q — Cross section of shaft, i.e., ralonuis, of spicule; R — 

 Cross sections of gubernaculum and blade, i.e., lamina of spicules) - 

 T-Y — Spironnura nffine (T — SpinOes and gubernaculum cleared in_ 10 

 per cent NaOH) ; U — Gubernaculum and spicular ala in longitudinal 

 section: V — Intestino-recta] valve and dorsal gland of female, longi- 

 tudinal section: W-Y — Sections of female through intestino-rcctal region 

 showing dorsal and subventral rectal glands and their orifices). Z — 

 Trickuris kuis (Cross section of male near cloacal opening). AA — T. 

 trichiura (Cross section near cloacal opening). BB — T. sui/t (Cross 

 section of cloaca with spicular pouch about to emerge from its walls: 

 according to Kauthcr more posteriorly the cloacal walls completely 

 surround the spicule forming a double layer). CC — 7'. siiiy (Recon- 

 struction of male tail: ac-cording to Rautlier the internal lining of the 

 cirrus is continuous with the cloacal lining anteriorly and is not the lin- 

 ing of the spicular pouch. The ut^per part of the cloaca has a double lin- 

 ing, the two layers fusing proximally). DD — T i^ulpi^ (Tail of male 



cleared in phenol). EE — Protostrongylus auslrinrtm (Gubernaculum and 

 spicules labelled by Gebauer: correct terminology in parenthesis) . FF-HH 

 — Pmtttstrntii/iihis ritpricaproe (Gubernaculum in various views). II 

 — P. korlii (Gubernaculum): JJ — P. raillifli ( liubernaculum ) . KK — 

 P. leurkurti (Gubernaculum). LL — Cy:<toeuiitu.t ni{/rfsrt'n« (Guber- 

 naculum). ilM — Spironoura affine (Cross section of male at junction 

 of rectum and vas deferens showing orifices of dorsal, ordinarj- sub- 

 ventral and sccondan,- subventral rectal glands; cuticle is absent in 

 region of gland orifice). NN — Dirlyornulug Jilnria (Lateral view of 

 male tail showing spongy type of spicules). OH — Fiilcauslrn liimb- 

 dienniji (\'entral view of rectal region of prcadult nuile showing spicu- 

 lar primordia). Z. BB & CC, after Raulhcr 191 H. /.ool. Jahrb., Abt. 

 Anat. v. 40. AA, after Kauther. 1909, Ergeb. u. Fortschr. Zool. v. 1; 

 EE-HII. after (icbauer, 1932. Ztschr. Parasitenk. v. 4: Il-I.b. after 

 Schulz. drlov & Kutass, 1933, Zool. Anz. v. 102; NN', after Yorke 

 & Maplestone, I92(i Nematode Parasites of Vertebrates^ 0( 

 .Seurat, 1920, Hist. Xat. Nernat. Berberie: remainder original. 



119 



