背腺

扫描电镜观察表明，孵化第32&36天的胚胎背部第二行鳞的各列鳞片表面均有背腺腺孔，以后逐渐出现少数不规则的退化，孵化第58天以后，绝大多数背腺腺孔消失。

Observation under scanning electron microscope revealed that there were dorsal gland holes on surface of every dorsal scale in the second row of earlier embryos , and afterwards , a few of gland holes degenerated gradually in an irregular way .

第38天，背腺腺泡明显，腺上皮为复层上皮；

At the 38th day of incubation , dorsal gland vesicles with stratified epithelium were evident .

背食道腺开口距口针基部2.1&3.7（2.5）μm。

Distance from dorsal esophageal gland orifice to stylet base is 2.1-3.7 ( 2.5 )μ m.

孵化第28天，背中线左右两侧第二行鳞片处的表皮内陷形成实心的背腺腺芽；

At the28th day of incubation , solid dorsal gland buds were formed from the invaginated epidermis of the second row scales at the either sides of dorsal central line .