362 M. Treviranus on the Structure of the Fruit of the Cruciferse. 



It is well known that the two-celled rudimentary fruit of the 

 Cruciferse is distinctly characterized by the fact that the septum 

 is not directed transversely toward the rachis or the centre of the 

 floral whorl as in other two-celled ovaries of Dicotyledons, e. g. of 

 Scrophulariacese, Gentianese, &c, but lies in the radius of it, and 

 that notwithstanding this, the same position of the two lobes of 

 the stigma occurs as in the families just named, that is, one is 

 curved outward and tlie other inward, consequently their relative 

 position corresponds with the direction of the septum. If we 

 examine the framework of this fruit in reference to the vascular 

 bundles of which it is composed, we usually perceive four, which 

 spring from the receptacle where it becomes somewhat expanded 

 to receive the fruit, namely two which ascend in the thickened 

 border of the septum on the anterior and posterior sides, and 

 two, one of which enters the middle of each valve. The former 

 give off in their course, in many-seeded silicles, branches passing 

 inward which serve as funiculi to the ovules ; they must conse- 

 quently, according to the division established by Mirbel, be 

 called the trunks of the placental vessels. On the other side also 

 large and numerous lateral branches proceed from them into the 

 valves, there anastomosing with those presently to be mentioned 

 as specially belonging to the valves. Each trunk of the placental 

 vessels is considered by DeCandolle as composed of two cords 

 united together*, and according to the theory which regards the 

 placenta as the border of the valve, agreeing with the double row 

 of ovules on each side, it might be so ; but, if I except Biscutella, 

 where the vascular trunk appears divided on each side, I have 

 hitherto found it simple in all the ovaries of Cruciferse I have 

 examined, without trace of division or combination, and the same 

 observation has been made by others f. When the aforesaid cord 

 reaches the apex of the fruit, that is, the place where the valves 

 terminate, it is continued further in the style and ends beneath 

 the stigma in that remarkable manner which I described as oc- 

 curring in Primula and some other genera J, and have since dis- 

 covered to be general ; namely it spreads out into numerous ra- 

 diating large and small branches which are of equal height and 

 have thickened clavate terminations. The branches from both 

 sides are collected here, but although they are very closely ap- 

 proximated they by no means unite. 



With regard to the two vascular trunks, one of which passes 

 into each valve, and which, following Mirbel, are to be called 

 pericarpial or valvular vessels, these also are apparently never 

 wanting, at all events they are by no means absent in the genus 



* M6m. du Mus. d'Hist. Nat. vii. 190. 



f Trecul, Ann. d. Sc. Nat. 2 ser. xx. t 17. f. 3. 



J Zeitschrift. f. Physiol, iv. 128. t. 9. f. 4. 



