2 
Psyche 
[Mar. 
them before, and they were also mentioned by Ondemans 
(1906), Zebrowski (1926) and Cooley (1938). 
All these authors were mistaken in the interpretation 
of the function of the organ they had seen. The larvae 
of the Ixodidae do not possess any special respiratory 
organs. Only Samson (1908) correctly recognized that 
the so-called “larval spiracles” described by Salmon and 
Stiles were actually the terminal pores of integumentary 
sense organs. This correction was, however, overlooked 
up to quite recently. Even Vitzthum, in his account of 
the Acarina for “Bronn’s Klassen und Ordnungen des 
Tierreichs” (1940), adopted in detail the description and 
views of Delpy. 
K. W. Neumann (1942) and Elishewitz (1942) first re- 
examined these structures in an attempt to decide 
whether they were respiratory organs or integumentary 
glands. Serial sections of larvae of Dermacentor, Hce- 
maphysalis, Hyalomma and Ixodes convinced Neumann 
that neither the Ixodinae (Prostriata) nor the Khipi- 
cephalinae (Metastriata) have respiratory organs and 
that the structures thus far interpreted as spiracles are 
really integumentary glandular organs. 
According to Neumann, these organs are in a direct 
view more or less oval in outline. “A broad ellipsoid 
chitinized frame at the periphery is attached to the sur- 
rounding cuticula by means of a narrow, prominent, 
striated edge. The lumen also is oval and contains two 
parallel, non-contiguous lips. Two small protuberances 
of the frame extend on each side into the lumen, keeping 
the lips from touching each other. By lowering the ob- 
jective, a small circular opening may be recognized in 
the center between the lips.” 
“In a side view of the entire organ or in a section, the 
structure is also more or less elongate oval. The walls 
consist of a rather thick layer of chitin, decreasing in 
thickness from the base toward the surface opening. A 
short duct leads from the base toward the interior of the 
body. On either side of the mouth of this duct a tooth, 
anchored to the base of the organ, extends up into its 
lumen. Serial sections show that these teeth arise from 
a folding of the walls. Their length is approximately 
three-fourths of that of the entire organ.” 
