Puchkov V F
Arkh Anat Gistol Embriol. 1979 Apr;76(4):32-41.
Normal development of spurs and horny squamae have been studied in histological preparations obtained from the skin of tarsometatarsus in 8--16-day-old embryos. During the first, initial stage of development, by means of rearrangement of cellular matter and cell migration, three main parts of the spur are layed down -- the horny cover, the spur body and the fibrovascular cushion. For the second stage, vigorous growth of the spur germ at the expense of proliferative activity of its cells is characteristic. At the third stage (after hatching) in males, the spur body outgrows and the bony core is formed. Morphogenesis of the horny squama can be devided into two stages. At the initial stages by means of condensing cellular elements, squamous papilla and horny shell are layed down. The fibrovascular cushion is absent. The second stage is similar to the spur one and is characterized by growth of all the germ parts at the expense of cell proliferation. Comparing morphogeneses of the squama and the spur, it is possible to conclude that phylogenetic transformation of the squama into the spur is performed by two means (modi) of phyloembryogenesis: by means of adding new signs of development to the initial terminal stages of its morphogenesis.
已对8至16日龄胚胎跗跖部皮肤的组织学标本中距刺和角质鳞片的正常发育进行了研究。在发育的第一个初始阶段，通过细胞物质的重新排列和细胞迁移，距刺的三个主要部分得以形成——角质覆盖层、距刺主体和纤维血管垫。在第二阶段，距刺原基以其细胞的增殖活动为代价进行旺盛生长是其特征。在第三阶段（孵化后），雄性的距刺主体生长并形成骨核心。角质鳞片的形态发生可分为两个阶段。在初始阶段，通过细胞成分的凝聚，鳞状乳头和角质壳得以形成。此时没有纤维血管垫。第二阶段与距刺的情况相似，其特征是所有原基部分以细胞增殖为代价生长。比较鳞片和距刺的形态发生，可以得出结论，鳞片向距刺的系统发育转变是通过系统胚胎发生的两种方式（模式）进行的：即在其形态发生的初始末期阶段添加新的发育特征。
