The manual begins with an objective of acquainting students with various laboratory equipments essentially required for practical exercises and a student is supposed to possess them. It follows with a set of instructions to be followed by students while working in the laboratory. Author deems it necessary that a student shall be well-versed with the structure and functioning of microscope and the precautions to be taken while working with the microscope. It also deals with the general methods of microscopic preparations, preparation of fixatives, stains and other reagents and the procedure of preparation of permanent stained slides for microscopic studies. The book includes general characters and classification of various invertebrate phyla, the study of musecum specimens and permanent slides under respective phyla and the sections passing through various regions of the body of certain specimens included in the curiculum. This also deals with the major, minor dissections and mountings. Wherever necessary, the collection and culture methods have also been discussed. Text also includes study of electron microscopic structure of cell, cell organelles, cell division (mitosis and meiosis), study of special types of chromosomes and identification of sex by sex chromatin. The systematic study of different invertebrate phyla provides important distinguishing characters, classification and important examples. Practically all the desired and important museum specimens and slides have been discussed and the comments are arranged in a sequence as students are supposed to present in the examination. The comments are brief and to the point.