2 Adams, Breeding Habits of the Common Mole. 



on the same lines ; and certainly the animal does not 

 come to its full growth till its second year. 



As to the second one can only surmise, my opinion 

 being that they neither pair nor live together. It was 

 Lecourt who pointed out the difference between the 

 plan of the encampment of a male and that of a female, 

 the male's encampment having a more or less straight 

 main run, while that of the female is a mere network of 

 runs without any apparent system. That this is so I have 

 repeatedly found to be the case. Whether they occupy 

 the same nest during the pairing season is uncertain, but, 

 judging from the size of the dry nucleus of the nest, it is 

 probable that only a single individual occupies it. 



Number 4 seems very difficult of solution owing to 

 the difficulty of observation and of keeping a captive the 

 necessary length of time, which must be about four weeks. 



The present notes contain some observations on the 

 last of these problems. 



Breeding nests. The females make special breeding 

 nests shortly before the young are born. These nests though 

 usually very slight and simple in construction, are some- 

 times as large and complicated as the winter fortresses. 

 The slight, simpler nests are often mere excavations under 

 the upheaved turf, and are, I think, the work of the young 

 does ; while the older and more experienced females 

 make the more elaborate preparations. There is one 

 almost constant difference between the winter fortress 

 and the breeding nest, and that is the absence of a bolt 

 run in the latter, and the persistence of it in the former. 

 I have, however, found two examples of breeding nests 

 with bolt runs ; and, of course, circumstances sometimes 

 prohibit the making of a bolt run in the winter fortress — 

 as in the case of the soil being waterlogged. On one 

 occasion I found two contiguous breeding nests in the 



