**8.3 Germinal (inner) layer**

This is the inner layer of hydatid cyst, a cellular living layer containing nuclei and associated with the lamellar layer by fingerprints formed by the germinal layer [20, 24]. It acts to protect components of the cyst and controls the osmotic pressure of the cyst wall [25]. The buds are formed from the germinal layer and grow toward the cavity of the cyst, and after the buds become vacuolated and stalked, the process of forming buds from the inner layer of cells begins from

**Figure 4.** *Cross section in the hydatid cyst [20].*

those cavities that lead to the formation of protoscolices [26]. The fertility of the aqueous cyst is determined by the presence of protoscolices, their increasing growth, and their association with the germinal layer, as well as other criteria for determining the cyst fertility through the white color and thickness of the germinal layer [27].
