The breeding season extends from May to November, and during this period each female appears to have several litters, each consisting of from four to eight or even ten--but usually five, six, or seven--young, although she has only six nipples. Putting it at three litters of six as an average--eighteen in a season--we get an enormous possible increase of Shrew population. Yet the numbers observable from year to year are fairly constant; and in considering the high birth-rate we have to allow for the heavy bill of mortality. Though Shrew-flesh is not to the taste of all carnivorous creatures, and its musky odour makes it actually repellent to some, this does not in all cases protect the Shrew from death. Cats, for example, kill many Shrews, but will not eat one. Dogs also account for many Shrews, and will sometimes essay them as food, though their stomachs refuse to deal with the unpleasant musky morsel. From the latter part of summer onwards dead Shrews are quite common objects of the countryside; and various theories have been set up to explain the phenomenon, for these dead bodies are mostly without any signs of maltreatment, either by tooth or claw. It has even been attributed to an autumn epidemic afflicting Shrews alone; and to the influence of fear caused by a thunder-clap or the mere breaking of a twig near by. But apart from this mysterious mortality, Owls levy a heavy toll upon the Shrew, as is evident from the indigestible "casts" thrown up by these birds. Other birds of prey, such as the Kestrel, are known to take their share, and a further considerable number are claimed by Magpies, Jackdaws, Stoats, Vipers, and Smooth Snakes. Then, again, numerous males fall victims to the jealous fury of their own sex, which leads to fierce and fatal battles. But, as already stated, there are seldom any indications of such encounters on the bodies of these autumn dead, and the only conclusion that appears tenable is that they have died from what a coroner's jury would term "natural causes." Mr. Lionel Adams, who has made special investigations into this matter, suggests that the natural cause is senile decay. He points out that young Shrews moult before winter, the process beginning in September and being completed by November, getting a darker and thicker coat than the light brown one they have worn hitherto. The progress of the change can be watched. It begins on the lower part of the back and extends gradually to the neck, head and face. In spring this darker coat is exchanged for a shorter and lighter one. _But in their second autumn there is no resumption of the winter garb!_ The natural span of a Shrew's life is fourteen months as the maximum; and Nature does not go to the expense of winter clothing for creatures that will not live to wear it.