40 M. Oscar von Grimm on the Agamic Reproduction 



for the attachment of the ovary*. But the question as to the 

 course of this cord, and also as to its point of attachment, has 

 remained unsolved bj me. I cannot say whether it attaches 

 itself to the Malpighian vessels, as in the Cecidomyid larvae, 

 according to Leuckart f and Metschnikow ^, or to the adipose 

 bodies on the one hand, and the intestine on the other, as is 

 asserted of the same larva by Ganin §, or, finally, whether it 

 runs to the dorsal vessel, as has been proved to be the case in 

 many perfect insects by Leydig || ; for latterly I had very few 

 young larvae, and in older ones it is almost impossible to solve 

 this question, as the ovary at this time becomes very tender, 

 so that it breaks up into fragments at the least touch. Un- 

 fortunately I have never succeeded in making a preparation 

 of a mature uninjured ovary — that is to say, at the time when 

 some ova are already perfectly developed but have not yet 

 fallen out into the body-cavity. Even when the ovary still ap- 

 peared quite strong and uninjured, when it could still be pushed 



* It will be superfluous now to discuss the opinion of Johannes Muller 

 that the lumen of this filament passes into that of the dorsal vessel, so 

 that the whole of the ovarian tube would be nothing but an altered 

 blood-vessel, and the ova be developed directly from the blood, seeing 

 that, by Leydig's investigations, it is completely demonstrated that this 

 union does not occur, and that only the peritoneal envelope passes into 

 that of the dorsal vessel in some insects, whilst the ovarian tubes termi- 

 nate csecally before reaching the heart (Leydig, ' Der Eierstock &c.,' 

 pp. 45-49), Moreover this was proved long before (in 1849, and therefore 

 twenty years ago) by Meyer (Hermann Meyer, ' Ueber die Entwicklung 

 des Fettkorpers, der Tracheen imd der keimbereitenden Geschlechtstheilen 

 bei den Lepidopteren," Zeitschr. fUr wiss. Zool. Bd. i.), who expresses 

 himself as follows : — " We often see definitely that this point terminates 

 cceeally at the dorsaLvessel ; and by this alone the signification of a vessel 

 (which has frequently been ascribed to it) would be contradicted, even 

 if the recognition of the significance of this cord did not unconditionally 

 exclude any such opinion" (/. c. p. 183). 



t " Die ungeschl. Fortpfl. der Oecid.," Archiv fiir Naturg. 1865, p, 290, 

 fig. 2. 



X Embr. Studien, Taf. 24. fig. 4, and Zhur. Mni. Par. ;Pr. 1865, May, 

 p. 107. 



§ Zap. Imp. Ak. 1865, p. 46. 



II ' Der Eierstock &c.' It must, however, be remarked here that in 

 the flies (e. g. Musca dotnestica) the ovaries do not attach themselves to 

 the dorsal vessel (Leydig, I. c. p. 34). Meyer also, who has already been 

 quoted, says, with regard to the Lepidoptera : — " A point (of the adipose 

 body) regularly goes ofi" anteriorly and attaches itself to the dorsal vessel ; 

 this subsequently serves for the attachment of the testis to the latter, 

 and in the ovary it becomes the thread which runs from the anterior 

 extremity of the ovary to the dorsal vessel " (I. c. p. 138). Under the 

 name of the point (Zipfel) of the adipose body, Meyer means the perito- 

 neal envelope of the ovary, as he himself states (p. 182), when he says 

 the envelope " bears the character of an adipose-body lobe of the parti- 

 cular kind of adipose-body lobes which are arranged around the dorsal 

 vessel." 



