6 Trans. Acdil. Sci. of SI. Louis 



iiaiy time stH'ins to hi* lit'tceii dt sixteen ila\ s. Early 

 broods take longer, late hroods a shorter time, so that 

 the weather, directly or indirectly, seems to be the cause 

 of these irregularities. 



From tile a])i)earnnce of the first yoiing to the hatch- 

 ing of the last i^y:^ in the same nest a difrerence of two, 

 three or even four days is rather the rule than the excep- 

 tion, and this tends to show that incubation may have 

 set in before the last c^f::;'^!; was laid, and it may be the 

 effect of the high temperature in the boxes during day 

 time, while the female covers the v'fii'f!;^^ at night and in 

 the morning. Oviposition takes place in the morning. 

 The remarkably large number of addled eggs, reaching 

 as high as 20 to 25 per cent, may possibly be accounted 

 for by this s]iontaneous incubation and subsecjuent 

 cooling. 



When tlie young Martin is six days old its eyes begin 

 to o])en. and when it is twelve days old it has already 

 strength enough to crawl out of the nest and take ])osi- 

 tion under the door. Here all the imnates, numbering 

 often four to six, are seen, closely packed, stretching 

 their uecks and greeting every approaching object with 

 mouths wide ojien. At this ])e!-iod the parents are ke]it 

 busy in ap]ieasing theii- hunger, and lai-ge inimbers of 

 dragon flies, soft grasshoi>pei"s and other substantial 

 morsels disap]>ear in the capacious throats. Sometimes, 

 however, the insect ]>roves to l>e too large for one swal- 

 low, when the ])arent bites it in two, but otherwise no 

 dressing of wiugs or legs is done. In order to facilitate 

 the work of digestion, possibly also for the sake of their 

 chemical constituents, small snail shells whi<-h they 

 gather on the sandbars are fed along with the insects, 

 and some knowing mothers descen«l into the chicken yard 

 to pick up of:^f!; shells for an extra dish. T^iecea of broken 

 china, found in the stomachs of young Martins, were 

 probably finl by mistake. Rut the busy old ones not only 



