1(32 



External intercostal type, 



Internal intercostal type, 



Transversus thoracis anterior type, . . 

 Trans versus thoracis posterior type, 

 Rectus thoracis posterior type, 



Serratus posticus inferior. 

 Iliocostalis lumborum. 

 Multifidus. 

 Rotatores. 



Interspinals et Spinalis dorsi. 



It may not be straining this system of ideal homotypy of muscular 

 development too far to say, that in the muscles'of the perineum we have 

 these types represented to a very perfect degree : the erector penis 

 being local representative of the external intercostal groups ; the 

 transversus perinei representing the internal intercostals ; the levator ani 

 andcoccygeus being the homotype of the transversus thoracis posterior, 

 the compressores urethras of "Wilson and Guthrie taking their place as 

 transversales anterior, while the accelerator urinse is the conjoint form 

 of the same type as the rectus anterior. 



The muscles of the neck present us with little difficulty in their 

 reduction to the typical structure, but the traces of cervical ribs are 

 very obscure in many instances, although some of them are clear and 

 constant. The first cervical rib is indicated by the pre-sternal points so 

 often present, and by the completely developed bone in rare cases, such as 

 the instances recorded by Lud wig Stieda, of Dorpat,Yirchow's "Archiv," 

 1866, p. 425. A second we have indicated by the ordinary tendinous 

 intersection in the omohyoid and sternohyoid muscles, as indicated by 

 Henle, who, in speaking of it, says — " Diese schne hat wie sich aus den 

 varietaten des muskels erschlessen laust die Bedeutung einer Eippe ; der 

 hintere bauch ist eine serratuszacke, der vordere ein dem sternohyoidens 

 der ja auch theilweise vonn Bippen entspringt, analoger muskel," &c. 

 " Muskellehre," p. 116. A third cervical rib is indicated in the oblique 

 line on the ala of the thyroid cartilage, and a fourth in the body of 

 the hyoid bone. Taking these into consideration, we may reduce the 

 neck muscles under the following heads : — 



1. External intercostal type, Scaleni anticus and posticus. 



'2. Internal ,, Scaleni medius and minimus. Anterior 



belly of omo-hyoid. 



3. Transversus costalis anterior type, . . Sternothyroid, thycohyoid, crieothyoid. 



4. Transversus costalis posterior type, . . Recti capitis antici. Longus colli. 



5. Rectus anticus, Sternohyoid. 



Of the posterior part of the neck we find the antithetic muscles of the 

 series to be — 



1. Exo-intercostal type, Splenius capitis et colli. 



2. Endo- ,, ,, Transversalis colli, et trachelo-mastoid. 



3. Transversus costalis ant. type, Semiopinalis colli, multifidi, complexus. 



4. Transversus costalis post, type, Rotatores. 



5. Rectus type, Interspinales, rectus posticus major et mi- 



nor. 



There is still one of the neck vertebrae unaccounted for in this 

 enumeration, namely, that between the hyoid bone and the ramus of 

 the lower jaw; and in this space we have the stylo-hyoid, digastric, 



