I may say at once that I think the appellant's construction of the Act is correct. I can find no basis in the Act for a conclusion that the appointment of a constable may be terminated in the unfettered discretion of the Chief Commissioner before the period of probation has run its course. On appointment a constable becomes a member of the police force for all purposes save only that his appointment is subject to a period of probation of two years. In this context the word "probation" has the effect of suspending the final appointment until the appointee "has by his conduct proved himself to be fit to fill it": Jowitt's Dictionary of English Law, 2nd ed. (1977), vol. 2, p. 1437. I would add the word "capacity" to "conduct", thereby reflecting more accurately the definition of the term in the Shorter Oxford English Dictionary, 3rd ed., vol. II, p. 1676, namely: "2. The testing or trial of a person's conduct, character, or moral qualifications." No necessary conclusion as to the security of tenure that is to be enjoyed by a probationer during the period of probation can be drawn merely from the concept of probation. One must look for indications from the context. If there were no indication to be found in the Act or the regulations then there would be much to be said for the argument advanced for the Chief Commissioner that it would be an absurd understanding of probation if notwithstanding that a probationary constable clearly demonstrated his unsuitability early in his period of probation that his appointment could not be terminated before the expiry of the period. On the other hand it might be argued that the appointee is entitled to security of tenure during the term in order to prove himself. But these considerations are of no consequence in the present case because the Act in my view is quite clear. The effect of s. 8(4) is to confer on a constable whilst on probation precisely the same security of tenure that is enjoyed by any other member of the police force below the rank of Assistant Commissioner. No constable, whether or not undergoing a period of probation, may be discharged from the police force otherwise than in accordance with the provisions of the Act and the regulations. The word "discharged" in s. 8(4) is entirely apt in its application to the termination of the appointment of a constable on the expiry of the period of probation. To discharge a person is to release him from an obligation: Jowitt , vol. 1, p. 619. On appointment a constable is required to take an oath that he will well and truly serve as a member of the police force of Victoria "until I am legally discharged": Form A, Second Schedule. When a period of probation has run its course a decision not to confirm an appointment will result in the appointee being "legally discharged" from his oath. If the decision is made in accordance with reg. 212 then the provisions of s. 8(4) will be satisfied. They will also be satisfied if during the period of probation a constable is dismissed for proven misconduct by order of a Police Discipline Board in accordance with the provisions of Pt V of the Act. There may be other provisions under which the service of a member of the police force may be terminated - see, e.g., reg. 1302 - but the conclusion which is inescapable is that the Act and the regulations provide a code which deals exhaustively with the circumstances in which that result can be achieved. In arguing that he may dismiss or discharge a constable on probation at any time, the Chief Commissioner is asserting the same power as is given to him expressly, in relation to police cadets, by s. 9(1). In my opinion, it is not possible to imply such a power from s. 8 of the Act.