iQio] The Egg of the Walking Stick 89 



declare that the minute structure of this curious egg-capsule 

 cannot be distinguished histologically from plant-structure." 



Among the leaf-insects the resemblance of the eggs to seeds 

 is especially marked. Nab* as early as 1854 has compared the 

 egg of one of these leaf-insects to the seed of the "Belle-de- 

 Nuit {Mirabilis Jala pa)." Henneguy (5) in the case of the egg 

 of Phyllium crurifolium claims that, "Sa forme est celle d'un 

 akene d'Ombellifere, et represente, par example, la moitie d'un 

 jeune diakene de Conium macnlaitim. L'oeuf diftere de I'akene 

 d'Ombellifere en ce que son opercule reguHerement conique, est 

 situe au centre de sa face superieure, tandis que le style conoide 

 de i'akene est aplati sur la face commissural. " Morton (12) 

 in this same species writes that the ''egg has been confused with 

 a seed of Mirabilis and Coniom!" 



According to Stockhard (18) the walking-stick, Aplopus 

 mayeri, is found only on its food plant, Suriana maritima. ' ' While 

 one may find a close resemblance in size and color between the 

 eggs of Aplopus and the seed of Suriana, both of which fall 

 from the branches to the ground, where they are obscured among 

 the debris" yet the eggs differ from the seeds considerably in 

 shape. 



The eggs of Diapheromera femorata were shown to a number 

 of botanists, and with one exception, all mistook them for seeds. 

 The botanist who did not fall into this error broke the egg 

 before giving his opinion. When asked as to what seed the egg 

 resembled all failed to recall any particular one. A leguminous 

 seed, such as a small bean, was suggested, but none could be 

 found in the natural habitat of Diapheromera, that resembled its 

 egg in size and color. 



If these botanists are unable to distinguish the egg of a walk- 

 ing-stick from a seed, can a grain-eating bird distinguish between 

 the two? If a bird were to feed on the seeds of the Suriana mari- 

 tima which resemble the eggs of Aplopus mayeri in size and color, 

 could the bird discriminate between the two, on account of a 

 difference in shape? 



Goldi (4) in the case of the eggs of two Brazilian walking- 

 sticks raises the question as to how far this imitation is useful 

 in the protection of these eggs. Grain-eating birds may eat the 

 egg but general insectivorous birds would probably mistake it 

 for a seed and leave it untouched. The protective dress of the 



* Quoted from Henneguy 's (5) paper. 



