HANSEN AND SÖRENSEN: THE ORDER PALPIGRADI. 235 
7 
Though we have only once in a way been fortunate enough to 
observe this gland (and even then scarcely in its full length), 
we feel bound to say that Grassi’s comparison of this gland in 
Koenenia is not correct. In structure the above-mentioned tu- 
bular gland in Aoenenza does not agree with the pouch-shaped 
»Krohnian gland» in Opéliones. On the other hand, there can 
scarcely be any doubt that it corresponds to the excretory glands 
which in the higher Avachnida (Aranee and » Arthrogastri») 
just have their orifices on the sides of the cephalothorax and 
not — like the Malpighian tubes of the Insects — in the rec- 
tum!®, And the structure of the afore-mentioned glands in 
Koenenia seems to be exactly the same as the excretory ones 
in Opzliones. 
Grassi already established Aoenenza as the type of a par- 
ticular order of Arachnida which he called Microtheliphonida. 
politica de Chile. Zoologia. Tomo cuarto. Paris 1849). About the fluid 
we read (p. 19) »su olor particular y muy fuerte, que imita al del äcido ni- 
trico 6 al de las ayellanas rancios [a rather curious alternative; at least the 
first suggestion is extremely unfortunate], La anatomia de algunos individuos 
vivos nos ha probado que este liquido estaba contenido en dos bolsas ovales, 
una a cada lado del céfalotérax, y que salia cerca de la cabeza cuando el ani- 
mal se hallaba perseguido 6 en peligro.» 
In Opiliones Laniatores these glands contain an oil which (combined with 
the urine) is let out when the animal is exposed to danger. As far as we 
know, Loman (Bijdrage tot de Anatomie der Phalangiden, Amsterdam, 1881) 
is the next author who after KROHN has examined this gland in Op. Palpa- 
vores. LoMAN who knows the opinion put forth by one of us concerning 
this organ in Of. Zaniafores says (p. 15) that he must leave the question 
about their function undecided. ‘This year one of us has examined them in 
Phalangium parietinum, they contain no oil, and their contents do not seem 
to be let out when the animal is in danger, — But we may add that, accor- 
ding to kind information from Dr. Fr. PURCELL in Cape Town, there can 
be no doubt that in a very interesting form (of which we hope to give a de- 
scription next year) closely allied to S¢v/oce//us, they are stink-glands. 
18 The accessory glands of the intestinal tube in Arachnids known by 
the name of »Malpighian» tubes cannot be said to correspond to the Malpi- 
ghian tubes in the Insects. For though it must be confessed that there is no 
full agreement about the fact, recent embryological researches seem to show 
that the above-mentioned accessory glands of the intestinal tube in Arachnids, 
originate from the entoderm, not from the ectoderm, 
2 
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