The investigations were carried out in 100 pig fetuses from various prenatal period stadiums. The macroscopical analysis and morphometry were done. The growth of the lingual length was linear during investigated period. The proportion between anatomical parts of tongue defined between 52–59^th day of gestation. The quantitative and qualitative parameters of lingual morphology are independent from sex influence.

The development of the lingual mucosa was described. The investigations were carried out on foetuses from the 53^th, 59^th, 70^th, 97^th, 107^th and 114^th day of gestation. The stains: H-E, Masson-Goldner and Azan were made. The histological analysis of the mucosa was done. The first symptoms of the keratinisation process in the 97^th day of gestation was observed. In the 97^th day of gestation the gustatory buds were not covered by epithelial cells. In the fungiform papillae, the gustatory buds in the dorsal surface were ob- served till 114^th day of gestation.

Myometrium consists of circular and longitudinal smooth muscle layers, which are spontaneously active. Main hormonal substances modulating myometrial contractility are progesterone and estrogen. The amplitude, frequency, duration, propagation and the site of initiation of the contraction change in the course of follicular cycle. Electromyography, intrauterine pressure measurements and in vitro methods utilizing isotonic transducers are the most frequently used techniques in research of myometrial activity. The paper includes detailed description of spontaneous myometrial activity in large domestic animals regarding mentioned methods.