9. The slopes being honey-combed and disturbed by rodents, particularly in clay soils, clay marls, and clay loams; and upon submerged earthwork, and in certain districts in the tropics by a mollusk which will penetrate and even destroy rocks. 10. From one portion of a cutting being more exposed than another to disintegrating meteorological influences. 11. By the discharge of water from land drains following the old drainage course, and by the localisation of the surface or land water flow. 12. The improper or imperfect drainage of land outside a railway fence, causing land water to accumulate in and discharge itself through the slope, thus disturbing the established equilibrium. 13. By an interference with the natural flow of any underground waters. 14. By allowing water to accumulate in the gullet, or upon the formation during the process of the excavation of a cutting. 15. The local percolation of water through the slopes of a cutting from the defective construction, wrong location, or permeability of the surface of a drain upon the cess. 16. An accumulation of water caused by the unevenness of the slopes. 17. The acceleration and inducement of a flow through the slope of any water contained in land outside a railway fence, and consequent incitement to the land-water to exude. 18. Vibration. 19. Insufficient flatness of a slope either at the time of excavation or after exposure to meteorological influences. 20. The strain upon the face from lumps of earth being allowed to remain upon a slope during the construction of the works, or the gullet being excavated for a considerable distance in advance; the cohesion of the soil being thereby unduly and unequally strained. 21. By overweighting. 22. By unequal loading. 23. The establishment of spoil banks upon the cess, or the additional loading of the ground near and outside a railway fence, in soft soils having practically no cohesion or tenacity. 24. The excavation removed destroying the continuity of support, especially in soils partaking of a semi-fluid character. 25. The want of uniformity of the covering of a slope causing unequal percolation or exudation of water. 26. The neglect to fill up, or otherwise remedy, cracks or fissures in the slopes or cess. 27. By artificial or irregular consolidation either of the formation or slopes superinducing movement and weathering in any portion not so compacted. 28. From an accumulation of water behind a retaining wall at the foot of a slope, resulting in the stability of the wall being overcome by pressure. 29. By unequal pressure upon the foundations of a retaining wall at the foot of a slope caused by lateral over-pressure tilting it, or by its unequal settlement. 30. In sidelong ground, by the removal of support against the action of sliding, which, without artificial aid, may not be arrested until the slope of a cutting on the higher side approaches the steepest inclination of the face of the hill.