Of these other cases, the Indian bulbuls of the genus _Molpastes_ form a very remarkable one. In all places where two of the so-called species meet they appear to interbreed, and so freely do they interbreed that at the points where the allied species run into one another it is not possible to refer the bulbuls to either species. Thus William Jesse writes of the Madras Red-vented Bulbul (_Molpastes hæmorrhous_) (page 487 of _The Ibis_ for July 1902): “This bird, although I have given it the above designation, is not the true _M. hæmorrhous_. I have examined numbers of skins and taken nests and eggs time after time, and have come to the conclusion that our type is very constant, and at the same time differs from all the red-vented bulbuls hitherto described. The dimensions tally with those given by Oates for _M. hæmorrhous_, while the black of the crown terminates rather abruptly on the hind neck, and is not extended along the back, as is the case with _M. intermedius_ and _M. bengalensis_. On the other hand, as in the two last species, the ear coverts are chocolate. Furthermore, I may add—although I attach little importance to this—that the eggs of the Lucknow bird which I have seen are, without exception, far smaller than my eggs of genuine _M. intermedius_ from the Punjab. My own opinion is that the Lucknow race is the result of a hybridisation between the other three species.” Further, in Bannu, Mr D. Donald saw _M. intermedius_ and _M. leucogenys_ paired at the same nest. That gentleman could not possibly be mistaken on the point, as the latter species has white cheeks and yellow under tail-coverts, while the cheeks of the former species are dark-coloured and the patch of feathers under the tail is red. Similarly, Whitehead and Magrath, writing of the birds of the Kurram Valley (_Ibis_, January 1909), record that the former shot no fewer than twelve bulbuls, which undoubtedly appear to be hybrids between these two species. As these hybrids differ considerably _inter se_, there seems no room for doubt that they breed with one another and with the parent species. Symmetry in Nature Wallace’s third statement, that if the two sides of animals in a state of nature were alike, easy recognition would be impossible among numerous closely allied forms, reminds us forcibly of the sad case of the boy whose tailor was his mother. _Humanum est errare_: she made her son one pair of trousers that fastened up behind, so that the poor boy when wearing them never knew whether he was going to or coming home from school! If animals are able to recognise their mates, their bilateral symmetry does not seem necessary to enable them to distinguish their fellows from allied species.