Among children, both boys and girls, it is common to find that the copulation of animals is a mysteriously fascinating spectacle. It is inevitable that this should be so, for the spectacle is more or less clearly felt to be the revelation of a secret which has been concealed from them. It is, moreover, a secret of which they feel intimate reverberations within themselves, and even in perfectly innocent and ignorant children the sight may produce an obscure sexual excitement.[35] It would seem that this occurs more frequently in girls than in boys. Even in adult age, it may be added, women are liable to experience the same kind of emotion in the presence of such spectacles. One lady recalls, as a girl, that on several occasions an element of physical excitement entered into the feelings with which she watched the coquetry of cats. Another lady mentions that at the age of about 25, and when still quite ignorant of sexual matters, she saw from a window some boys tickling a dog and inducing sexual excitement in the animal; she vaguely divined what they were doing, and though feeling disgust at their conduct she at the same time experienced in a strong degree what she now knows was sexual excitement. The coupling of the larger animals is often an impressive and splendid spectacle which is far, indeed, from being obscene, and has commended itself to persons of intellectual distinction;[36] but in young or ill-balanced minds such sights tend to become both prurient and morbid. I have already referred to the curious case of a sexually hyperæsthetic nun who was always powerfully excited by the sight or even the recollection of flies in sexual connection, so that she was compelled to masturbate; this dated from childhood. After becoming a nun she recorded having had this experience, followed by masturbation, more than four hundred times.[37] Animal spectacles sometimes produce a sexual effect on children even when not specifically sexual; thus a correspondent, a clergyman, informs me that when a young and impressionable boy, he was much affected by seeing a veterinary surgeon insert his hand and arm into a horse's rectum, and dreamed of this several times afterward with emissions.