This study deals with the anatomical, histological and histochemical observations and the changes in the poll glands due to age, seasonal variations and castration. The male camels had two poll glands, one on either side of the mid-line of the poll region. The glands were present in the male camels at birth, while no visible glands were observed in the she-camels at any age. The weight and dimensions of the glands increased with age in the uncastrated camels, but the glands regressed after castration. The active glands were compound tubulo-alveolar glands. The tubules and alveoli were lined by simple squamous to high cuboidal epithelium depending on the secretory stages. The mild PAS-reactive apical blebs of the secretory cells were also positive for acid mucopolysaccharides and alkaline phosphatase. The myoepithelial cells around the alveoli and small ducts were PAS-negative. The intralobular ducts were lined by simple cuboidal epithelium. The stratified cuboidal epithelium lining the initial portion of the excretory duct abruptly changed into the stratified squamous epithelium which continued with the cutaneous epithelium of the skin. The ducts opened into the neck of the hair follicles above the level of the sebaceous ducts. The glands appeared to be modified apocrine sweat glands in the histological appearance. The interglandular connective tissue was reduced to thin strands during the winter months while, comparatively, in the summer months, the connective tissue increased. During the winter months of December to March the pungent coffee-coloured secretion from the glands was most profusing in those camels who were apparently in rut. The tubules and alveoli in such glands were lined by high cuboidal cells with apical blebs. During the summer months, the secretion was scanty except in severe exercises, and the glandular epithelium varied from simple squamous to low cuboidal.

The testicular seminal pathway in the camel is divided into two portions: an intratesticular and an extratesticular portion. The intratesticular seminal pathway consists of three portions: a ‘tapering terminal segment’ of the seminiferous tubules opening into the receptacle, the tubuli recti with three parts and the rete testis. The extratesticular portion consists of the rete testis, as an extension of the intratesticular portion and an elongated sac from which 6–7 ductuli efferentes originated. The tapering terminal segments are lined by modified Sertoli cells. Both, the tubuli recti and rete testis, are lined by simple cuboidal to columnar cells. The epithelium of the ductuli efferentes which, at its origin from the sac is simply cuboidal, gradually changes to an epithelium that consists of alternating groups of high-columnar ciliated and low-columnar non-ciliated cells. The strongly PAS-positive basement membrane of the ductuli efferentes is surrounded by a thin circular layer of smooth muscle fibres. The pseudo-stratified columnar epithelium of the epididymis is supported by an intensely PAS-reactive basement membrane. Morphological changes in the epithelium of the head and body regions of the epididymis due to seasonal variations are well marked in the camels of all age groups.

Histological and a few histochemical studies were done on the testes of 34 camels between 4 and 20 years of age, during three seasons: the tunica albuginea of the testes was composed of collagenous and a few elastic fibers. Isolated bundles of the smooth muscle fibers were observed in the capsule. The mediastinum testis and its radiating septula into the parenchyma also consisted of mainly collagenous and a few elastic fibers. The interstitial tissue was composed of Leydig cells and a network of reticular fibers. These cells increased in volume in the rutting period from December to March, and were distorted and reduced in volume in the nonrutting period from April to November. The seminiferous tubules were 113–250 μm in diameter, and were lined by many layers of spermatogenic cells and a single layer of Sertoli cells. The spermatogenesis was observed as a continuous process throughout the year, particularly in the camels between 4 and 15 years of age. Almost in all the testes studied, three types of spermatogonia, two to three layers of primary spermatocytes, rarely secondary spermatocytes and spermatids in two stages were observed. The spermatozoa were present attached to the Sertoli cells as well as free in the lumen of the tubules. The oval head of the spermatozoa was characterized by the presence of an elongated pointed, strongly PAS-positive acrosome.

Long term D-penicillamine therapy, especially when used to treat Wilson's disease has been shown to cause elastosis perforans serpiginosa, pseudoxanthoma elasticum perforans and other degenerative dermatoses. We report a 23-year-old male patient who presented with multiple firm papules, nodules over the neck, axillae, front of elbows for five years. He was a known case of Wilson's disease on long-term treatment with penicillamine for the past 12 years. The papulonodular lesions were non-tender and some were discrete while others were arranged in a circinate pattern. There was central scarring of the skin within the circinate lesions. In addition, there were several small yellowish papules on both sides of the neck which eventually became confluent to form plaques. Histopathology confirmed the diagnosis of elastosis perforans serpiginosa and pseudoxanthoma elasticum. He was treated with cryotherapy (using liquid nitrogen through cryojet) for former lesions. The lesions showed remarkable improvement after five sittings. Now the patient is under trientine hydrochloride (750 mg twice daily) for Wilson's disease.

SUMMARYSections of muzzle skin were studied from twelve Murrah buffaloes including seven females and five males ranging from 1½ years to mature animals up to 7 years old. The 130–1350 μ thick epidermis of muzzle rested on a PAS positive, argyrophilic basement membrane. The stratum lucidum was lacking. The stratum granulosum could not be identified in some animals. In such animals, a wavy, deeply eosinophilic layer was seen in the area of stratum granulosum and stratum lucidum.Lamellated nerve endings, 40–45 μ in diameter, and arteriovenous anastomoses, frequently appeared in the reticular layer of the muzzle dermis.The muzzle glands were lobulated, compound tubuloacinar and resembled the salivary glands morphologically. Their acini were strongly PAS reactive and acidic mucopolysaccharide positive. While intercellular secretory canaliculi were present, myoepithelial cells could not be observed. It is suggested that fine bundles of striated muscle fibres which run perpendicular to the skin surface might function to expel gland secretions. Most gland-cell nuclei were intensely Feulgen reactive and the cells revealed a moderate alkaline phosphatase activity. The intralobular duct system of the muzzle glands consisted of PAS negative intercalated ducts and mildly PAS reactive striated tubules. The simple cuboidal to columnar epithelium of the striated tubule changed to pseudostratified columnar type toward the larger interlobular ducts which were lined by stratified columnar epithelium. Toward their opening, the excretory ducts had stratified squamous epithelium. The lumina of the ducts frequently contained PAS positive and colloidal iron reactive secretory mass.