INVERTEBRATA, CRYPTOaAMIA, MICROSCOPY, ETC. 619 



life. Their anatomical observations, especially those as to the con- 

 siderable concentration of the nervous system, seemed to confirm that 

 hypothesis. 



M. Vayssiere considers that this opinion must now be abandoned, 

 as he has just seen the metamorphosis of two of the insects captui-ed 

 in April last. 



The following are the principal phases of this metamorphosis : — 

 Towards the end of May the amber-yellow colour of some of the 

 insects became darker ; and owing to their transparency he was soon 

 able to see the first outlines of the new individual, and two or three 

 days afterwards the animal cast off its pujial envelope, freeing itself 

 in the same manner as the ordinary Ephemeridfe, 



In the perfect state Prosoiyistoma almost exactly resembles Ccenis ; 

 its last segment is provided with three rudimentary bristles represent- 

 ing the swimming bristles it possessed during its aquatic state. The 

 anatomical modifications brought about by this metamorphosis are 

 reserved for a complete monograph on the genus. 



Piercing Organ of the Lepidopteran Proboscis.* — This organ, 

 which has already been described t by the author, Professor W. Brei- 

 tenbach, is situated at the end of the proboscis, and is designated by 

 him " liquid-piercer," or " opotrype," and its function is now con- 

 sidered. There are various forms which it assumes, but they all result 

 from the modification of simple hairs. Although a tactile function 

 has not been satisfactorily demonstrated for the hairs of the proboscis 

 by evidence of nervous end-organs in them, yet analogy and their 

 large size lead to such an inference. Turning to those more complex 

 appendages to the proboscis, the barbed hooks, we find that those 

 butterflies which possess them — as 0]:)lnderes and Egyholia — live to a 

 great extent by the juice extracted from the interior of fruits, a process 

 effected by the intrusion of the stout trunk into the rind and its subse- 

 quent withdrawal, when the backwardly directed hooks lacerate the 

 tissues and set free a quantity of juice. Direct observation of a similar 

 function in the " liquid-piercer " is not forthcoming ; this fixct, liow- 

 cver, speaks in its favour, namely that on the Alps a number of butter- 

 flies are seen to be occupied with flowers which contain no lioney, 

 thrusting the trunk into them and remaining tluis employed for a 

 time ; if this process was really futile, it would soon cease to bo 

 repeated; but as it is not, it is probable that liquid is procured by tlio 

 laceration of the structures by the piercer. The structure of the organ 

 itself supports this assmnption ; the median point of that of Vaiwssa 

 is admirably adapted to pierce the delicate membrane of a juicy cell, 

 and the lateral points to break up more cells, so that where as many 

 as sixty piercers are i)resent, as in V. canhii, the eficct would be very 

 great, but only analogous to that already known to be produced by 

 the maxilljo of the humble-bees. 



In ojqiosition to this view stands Fritz Miillcr's opinion that they 

 arc " taste-rods " ; but to this it is re^jlied that their structure is 



• 'Eiitomol. Nucbrichleii,' vi. (18S0) p. 29. 

 t See this Jouruul, ii. (IS?*.)) p. 41. 



