966 CALIFORNIA ACADEMY OF SCIENCES. 



same or some other tree. The mammoni or third crop of 

 the caprifig has by this time advanced so far in develop- 

 ment that its interior flowers are just of the proper size 

 and age to suit the wasps (75). If there are no such figs 

 at hand the wasps will soon perish. Having lit on a mam- 

 moni the Blastophaga finds the fig -eye closed by scales 

 (76). But these scales are not impossible to penetrate. 

 In order to enter the fig the Blastophaga saws out a tiny 

 little piece of the outside edge of a top scale, which opens 

 to her an entrance between two scales. Next she pushes 

 herself under the scale and then zigzags herself through,^ 

 until she reaches the interior hollow of the fig. But her 

 efforts to get through between the scales have been tre- 

 mendous, and in so doing she almost invariably loses her 

 wings. They are always lost in the very beginning of her 

 work, and can be seen remaining, wedged in between the 

 outside scales just like feathers stuck under the band of 

 a hat. In order to ascertain the presence of the Blasto- 

 phaga in a green fig it is not always necessarjA to cut the 

 fig open, as the presence of the wings of the wasp stick- 

 ing between the scales is a sure sign that the wasp has 

 succeeded in getting in. And even if the wings have 

 fallen off the little wound caused by the gnawing of the 

 wasp can be told by the minute drop of sap that has oozed 

 out and hardened. It is this drop of sap which was, re- 

 markably enough, for ages considered as being the real 

 cause of the setting of the figs. If no wing's and no gum 

 is seen on the scale it may be safely assumed that no 

 Blastophaga has entered. the fig in question. 



As soon as the now wingless Blastophaga has entered 

 the figs she hurries down to the gall flowers there to de- 

 posit her eggs. Of these she only inserts one in each 

 flower. The egg is always placed in the same way and 

 in the same particular spot in the flower. This particu- 



