The second matter, however, cannot be disposed of nearly so satisfactorily. It is difficult to determine with any approach to exactness the respective proportions of the deaf in the several states of school age who are out of school. The census does not give us definite information on this point; and though the school authorities themselves are usually aware of conditions in their respective states, they seldom have the means of fully ascertaining. But we may learn something of the general situation. In the reports of some of the schools complaint is not infrequently made as to the number of deaf children out of school who should be in, and in a portion the number is said to be large.[532] The proportions, furthermore, found in attendance in the different states in comparison with their total population, or with their total deaf population under twenty years of age, indicate that the attendance in some states is far greater than in others, which means that in the latter a relatively smaller part are in school.[533] It would appear, then, that the number of the deaf out of school who are of school age is probably not negligible in any of the states, and that in some it is very considerable.[534] The fact that the schools do not have their full quota of pupils is not all due to the refusal of deaf children to avail themselves of the opportunity for a schooling. It is in good part owing also to the failure of some of the pupils who attend to remain a sufficient length of time. In the preceding chapter we have seen what are the limits of attendance prescribed in the schools; but as a matter of fact a large proportion of the pupils do not remain the full period allotted, and in some of the schools an appreciable number do not remain the better or a substantial part of the term.[535] As in all schools, there is in the passing of the pupils from the years of childhood an increasing tendency to leave, and with the deaf this applies with no less force;[536] so that on no small portion of the pupils the work of the schools is not permitted to have full effect. THE NEED OF COMPULSORY EDUCATION LAWS FOR THE DEAF It is thus quite evident, however large the true proportion of the deaf who attend the school may be, and whatever the proportion remaining a satisfactory period may be, that in practically every state there are a certain number of deaf children not in the schools who should be there, and that the offer of the state to provide an education for all its deaf children is not availed of as it should be.[537] For the existence of this condition of affairs the schools are not to be held responsible. They are usually doing all they can to get the children in, and all the deaf if they will may receive an education. The cause lies further back: most often in the ignorance or short-sightedness of the parent.